May the 2012/2013 iMac not be the big fish?

Apple tends to do major updates every 2-3 years, like they did with the last iMac, so either next year or the one after will probably see a more substantial update.

That said, the current update last week or so was a pretty big one, the new power and graphics make it a good improvement over last years.

 

IMO they could only offer what Intel has to offer. Haswell just isn't that big of a step over Ivy Bridge.

Either way unless one has to have bleeding edge technology then the just released iMac will last the majority of users for quite a few years.

Your want/need should be able to determine whether or not to get it now and be happy. I don't think you're going to do much better unless you get a MacPro which will cost significantly more.

 

Next year will be a Haswell refresh on the desktop side however if Apple continues to use nVidia graphics, the 800 series should be a huge jump especially the (assuming it will be called that) 880M.

 

Fusion Drive, yes! The retina is very very unlikely until GPU's improve more, and touch screen is extremely unlikely unless OS X goes a major overhaul. And besides, not to drag out old stuff, but Steve Jobs made it clear there wasn't going to be a touch screen on a Mac anytime soon.