This delay in the new Macs seems more related to Intel not delivering on time. Apple is probably not too happy about the delay for Ivy Bridge.
But at this point Apple is in no rush. Ivy Bridge isn't that much better than Sandy Bridge. Macs are selling well. Apple has the luxury of being able to take its time designing and testing new form factors for the entire Mac line.
Clearly Apple are going to release new Macs, iMacs, MacBook Pros, MacBook Airs, and almost certainly a new Mac Pro. They are working hard on Mountain Lion which will help sell their new Macs. It's doubtful Apple would be working so hard on Mountain Lion if they were not highly committed to keeping the Mac line moving forwards.
We are very close to WWDC. Apple will probably underpromise and overdeliver with regards to the Mountain Lion release, like they did with Snow Leopard. We will almost certainly see new Macs at WWDC which will ship with free upgrades to Mountain Lion which will come out mid-summer. I doubt we will see any new hardware upgrades before WWDC which is now only about five weeks away.