Spose so - I don't know what people are using out there.

I don't think it was shipped in major distros at least (AFAIK) 
They all went from 2.95 to 3.1/3.2 

Perhaps stick an error for 3.0 in and wait if people are complaining? 

quoted

AFAIK it has never been widely used. If we assume 3.1+ minimum it has the 
advantage that named assembly arguments work, which make
the inline assembly often a lot easier to read and maintain.

There are a few places in the tree which refuse to compile with 3.1 and 3.2.

Really? Which ones? 

Haven't seen that and I still use 3.2 occasionally (it's the default
compiler on SLES9 and I believe on RHEL3 too)  

-Andi