Would it be financial suicide to not release an iPad1 version of my game and
build for ipad2,3 and iPhone4s only?
Performance issues on iPad1 are causing delays.
I do not think so. Generally, consumers have gotten to into the tradition of upgrading (mobile) computers every second year or every year (my camp).
Personally, i would say just to go with the newer iPads. However, I would suggest having the game on the iPhone 4 as well. At least here in the US, the iPhone 4 is still very popular and still has people who purchased it as ‘new’ (ie. before the 4S) who will be tied to it for another year.