I currently have a USP .45 full size Date Code  KF (1996?) That's DA/SA and I really like it.  I'm  wondering just what the big differences are between the USP and the P2000.  

In the future, I'll be in the market for a compact and I'd like to stick with a .45 so the USPc and a compact SIG are in competition.  Is the P2000 compact going to come out in .45? What are people's opinions of the P2000 compact?

Thanks in advance,
Mike

The big difference between the USP and the P2000 is that the P2000 has different grips, and a ambi slide release. Much like the old Walther P88.

The P2000 also comes with the HK LEM trigger, like you can get on the USP compacts. If you dislike the LEM trigger, you can buy a P2000 V3, which has DA/SA with decock, and no safety.

I think the HK P2000 is a great handgun. If you are a left hand shooter I think the P2000 is one of the best left hand guns on the market today. But if you are cheap like me, the USP compact can be found for $500 and less. The cheapest P2000 I have ever found was $675.

If you like the 45, and want to carry the 45 then you should look at the HK USPC.  Or the SIG 245. The Hk USP .45C feels better to me than the SIG 245. But that is just me.

There as been a lot of HK fans who would like to see a P2000 in .45 but it looks like we won't see one for a long time. HK is building a new 45 for the German Army, the pics can be found at HKpro.com and it looks like a combo of a USP and P2000.

I have a USP 45F and when they first came out, I handled a 2k... didn't like the 2k as much as the 45F.

the way it felt and that thingy on the rear of the slide.

The P2k's frame is not big enough to handle the .45 ACP so don't look for it any time soon.  They would have to do a new frame just like they did the USP and the USPC when they went to .45  (The "new" HK45 that is a cross between the USP and the P2K is full sized from what I understand).
The P2k is about the same size as the USPC so I don't see much difference other than the ambi slide release and interchangeable back strap.  The P2K is mainly LEM (V1, V2, V4, and V5) but V3 is SA/DA decock only just like the V3 on the USP/C, except the P2K decock is ambi by being on the back to the left of the hammer.  Me, I'll stay with the .45 in the USPC.  I like my .40 P2K well enough but DAO (even in V1) is not my cup of tea and neither is a decock only SA/DA.