In my opinion/ case, supporting sm2 als fallback is not a few minutes work

As a side note, two of my friends recently upgraded their PCs. One went to an Athlon T-bred to "some dual core athlon". The other went from a P4 some core 2. The former has a Radeon 4500, the other... a GeForce 6000. In both cases, shader profile 3 seems to be there and I believe they're pretty indicative of what non-core users might be acting.

That said, all my future development is going to target at least SM4. There's no reason in optimizing for hardware that won't exist anymore when you ship.

Thanks for the confirmation, I've removed all SM2 support and cleaned up my engine nicely :)