This is most definitely the case, with just Beth HRDLC (half normals) + SRO 2k (unoptimized atm) I can hit over 2GB VRAM around Windhelm. Most places lower but Windhelm is a killer for resources and where I am doing the majority of my stress testing. I haven't even gotten to weapons, armor, characters, FX, etc yet with my latest round of testing. For modded Skyrim I'd certainly say 3GB is a great thing to have.