Here's to hoping there will only be a 64-bit version of Win 10... This is an excellent opportunity to kill 32-bit OS for good.
I doubt very much it'll happen but I'll drink to it anyway. 32 bit is old hat and should have been retired with Win 7. 64 bit is the way to go because it uses hardware more efficiently and provides greater opportunity for growth... and given the rapid growth in hardware development, 32 bit OSes aren't going to keep pace.
I notice more and more that there are fewer 32 bit proprietary machines one sale these days. Most I see advertised or in stores are 64 bit with 4 or more gigs of RAM, so just maybe 32 bit OSes will die a natural death, if not with Win 10 then maybe with win 12.... if MS stays true to skipping a number to try distance itself from the last cock-up. This time it's the butt ugly icons and start menu, so not everyone's going to like Win 10.
Me, well I'll get Win 10 anyway, cos under the hood 'll be good, and I'll customise the heck out of it make the GUI respectable.