I'm also crossing over from the Palm Pre world and also found this limitation strange. I guess the Pre is the only phone out there allowing multiple activesync accounts?

I actually need three. I manage a data center infrastructure and use a separate email account for alert emails. The third, as per this thread, would be Google so I could have my personal calendar and contacts synced. I had it set up on my old smartphone such that after regular working hours, only the alert email account was set up in "push" mode.

No big deal though, for now I just have my pre at my bedside just functioning as a wake up alarm in case there's some service outage at work.