Is there really any problem with an infinate regresion of universes?

[Mudhammam]

No, it isn't. An infinite regress is a series in which each proposition is dependent on the one before it. You're describing propositions in parallel which are independent of each other, but each dependent on another common proposition. They're not the same thing. 

Yes, it is.   Neither theory nor observation insist the supposedly parallel propositions as you put it must be really independent of each other.   All that is required by the fact that our universe appears to be headed towards an end state very different from its initial state is each successive proposition is not required to actually be made from the end state of another.

I'm going to interchange "proposition" with "event" for clarity.
Okay, so, we should still presumably have to justify what it is that makes the first event in the succession different from all of those that follow it, if all of those that succeed the first event are connected in such a way that the next event's becoming entails the last event's perishing.