Actually, why don't raise the bar higher? SSE2 has been introduced in 2001 – that's 15 years to upgrade one's hardware and given my sad experiences with computers, I find it hard to believe anyone has that old PC that happens to run Arch. We used to advertise ourselves as optimized for modern processors. Our "i786" really should include SSE3. For the same reason I would not complain about requiring SSE4 instructions for amd64.
I also wish we had some data on SSE2 support across i686 machines. Perhaps we should upgrade pkgstats to record *all* the cpuflags? We would gain data for future decisions, too.
pkgstats seems to have lots of old data. It would be beneficial to start the statistics from scratch and include kernel modules as well to see if our config isn't overloaded. Bartłomiej