Well, I'm as much in favor of having a variety of guns on the market , as anybody, and I like this SCAR rifle just fine.

However, in the overall scheme of things, regarding it "replacing" the M16/M4, I really can't see it.

Especially now that time has marched on since the original SCAR competition, and there are other rifles out there now, and upcoming, that squarely can challenge anything the SCAR can do, and maybe even do better. And some are M4-based.

The minute you finalize on a design, that is the minute you start losing ground to the newer developments that are moving forward.
It's just the way technology is.
Eventually, everybody gets "leap-frogged" in some way or other.

Quoted: TWL, assuming that even if SOCOM picks up SCAR that Big Green will stick with M16/M4, what do you think are the chances of a "smaller" organization, say, oh, the USMC, also going SCAR? John

John,
As far as I can see, there is really no telling what is going to pan out with any of the service branches.
It's all so up in the air right now.
The SCAR certainly has a chance, and is in probably the best position right now, since it has the history of winning a trials program, and is somewhat in the driver's seat.
But, we've all seen the rug get pulled out from under things before, so who can tell?

Quoted: just curious which rifles you would put on that list ?

Well, of course I'd put our MGI package up against it, but we were too late for the SCAR trials, and only part of our package is even available because of these delays we've incurred. So, I'd have to put our modular system into the category of "part here, and part upcoming". MGI is the only system to be capable of providing both the "L" and "H" caliber platforms on a single gun with the same upper and lower receivers(that I know of). At this time, the MGI system is direct-gas-impingement operation, which may be a good or bad thing, depending on your point of view. A piston system can easily be added to this platform if desired, and we have experience in piston operated gun designs since introducing our first one in the 1970's under our original Bushmaster label(We owned Bushmaster back then). We also have a collapsible AR-type carbine stock instead of a folding stock, and that could also be considered a positive or negative, based on your point of view. We also have other features designed for the platform that go well beyond the SCAR trials requirements. Our main design thrust is sufficient modularity in one platform to be able to quickly and easily configure to nearly any changing requirements that might come up.

Then there is the XCR, which was almost a SCAR entry until they forgot to include the blank-firing adapter and were disqualified on the technicality. I guess nobody really knows yet how that would have fared in the competition. It has a piston, and a folding stock, and some caliber conversion ability from what I've heard about it.  So, that is here now.

And there is some possiblity from the Cobb rifles, but I'm not too familiar with them. They seem to have some of the desired features. Some of the Cobb stuff is here now, and some upcoming.

And there is the HK416/417 , although I'm hearing some stuff that it is too heavy and isn't as controllable as some would like. It didn't get entered in the SCAR trials, but it seems to have features that are aimed at that. These guns are here now, but not commercially.

And then there's POF, which is now playing the field with  light(AR15 sized) and medium(AR-10 sized) piston system platforms. One for the AR15 platform, and one for the AR10 type platform gives them  "L" or "H" type platforms for the needed calibers, similar to HK with their own design and improvments made.
And so is LW doing a very similar arrangement with their piston on the 2 different sized AR platforms, again similar to HK with their own piston design and other improvements.
Both these companies have their own unique designs, and I don't mean to say they are the same as the HK system, but just that they have dual AR-style platforms for the L or H requirements.
Obviously, both of these companies' guns are here now.

Exactly how any of these will actually fare in head to head competition against the SCAR would have to be seen. However, they are in the ballpark, and who's to say exactly what would eventually come out on top? In the real world performance area, there is no arbitrary set of rules/requirements to be met on paper, so it would be whatever really works best in practice in the field. In a completely open-class competition, no holds barred, or artificial rules set in place, there could be some interesting outcomes.

These are some examples, and I didn't mean to leave any others out, if I did.
Naturally, I'm biased towards the MGI system since I'm involved with it, but I tried to give a fair list of guns which could be competitors in their own ways.

I think that it shows that there are a number of companies responding to the perceived needs of these advanced weapons systems, and that technology is moving forward on more than one front.

Quoted: Then there is the XCR, which was almost a SCAR entry until they forgot to include the blank-firing adapter and were disqualified on the technicality. I guess nobody really knows yet how that would have fared in the competition. It has a piston, and a folding stock, and some caliber conversion ability from what I've heard about it. So, that is here now. Did that actually happen? If the XCR entry used a 22mm NATO adapter, why didn't someone just give them a $5 USGI BFA? DQ'ing the entry based on this tiny technicality is absurd. I am not even pro-XCR, but it just sounds kind of far fetched even for .GOV and .MIL procurement.

Well, that is what Robinson Arms claimed back when this stuff was happening.
They actually had an explanation like that posted up on their website at the time.
I know it was there, because I read it on their site.
They were pretty angry about it, and seemed to feel "robbed" of their opportunity to compete.
There was quite a bit of "hoopla" going on about it back then.
It's no longer on the website, and I didn't find it in a quick google search.

I don't know specifically what went on behind the scenes regarding the BFA.
All I know is that Robarms made that statement.
I assume that it is accurate, and I have no information to confirm or contradict it.

If anybody else knows more about it, maybe they can be more help.

Edited to add:
A little more Google searching yields this link to Robarms explanation.
www.robarm.com/xcrtm_modular_weapon_system_reje.htm