So is this Wednesday/Thursday no longer a possibility? I ask as I now believe Tuesday won't happen but a launch with the iPhone is that possible?
I don't see the iPhone as a problem as it's not really a new model so it can be released rather silently.
The iMac as well will not sport anything too extraordinary apart from the (probably rather big) spec bump. Thunderbolt is already available on MBP's, as is Sandy Bridge. No new form factors (or we'd have heard something pointint in that direction) so this probably isn't too big a thing either.
Hypothetically, one can conceive of reasons to release them at the same time. Because between iPad 2/MBP and WWDC they could use something to attract attention, and neither of these releases is big enough to do it on their own.
WWDC is approaching and I'm pretty sure they'll want to release the iMac some time before that.