Found this on their web site, looks like they understand what cusomers want.

"If the 1994 Assault Weapon Act is not renewed by Congress, any consumer purchasing one of the following new Smith & Wesson handguns at retail between August 15, 2004 and December 31, 2004 that did not include two high capacity magazines at the time of purchase will receive from Smith & Wesson, two high capacity magazines for their specific handgun (subject to federal, state and local restrictions) at no charge upon submission of the handguns model number, serial number and a copy of either the dated receipt or Federal Form 4473.

Model List:
All versions SW9
All versions SW40
All versions SW99's (excludes 45 ACP)
Model 910
Model 410
All variants 5906
All variants 4006"

Quoted: Model List: All versions SW9 All versions SW40 All versions SW99's (excludes 45 ACP) Model 910 Model 410 All variants 5906 All variants 4006"

And of course, it lists all models except for the model *I* bought. Shit.

You will still want to check out their site. I may have missed a line in my copy and paste.  good l;uck