I replied to your other post in the general N8 thread, Push appears to work with my Mail for Exchange connection, there is at most a 1-2 second lag between it appearing on the server and it arriving on the phone. I checked the nokia support forums and didn't see mention of problems with the push email, do you have a link to the thread?
I haven't verified with my non-MfE accounts but I noticed they have 'Soonist' vs an 'Always On' for their sync time, so it might not be true realtime on them, perhaps it polls every minute or something..
