I'm Android user and want to switch. I find it enormously annoying that all IM clients, skype, facebook, twitter, fring etc. pool incoming messages every 10-30 minutes.

How does it looks like on N900?

Let's assume I leave IM/Skype in the background and let the phone go into sleep/suspend/standby mode, put it into pocket etc. Will I get incoming IM's/Skype calls instantly? If yes, will I get at least 8h standby time in this mode on standard battery?

EDIT:
Let me add some details.

On Android, application can do one of three things to check incoming messages after phone goes to sleep:
- schedule timer, to wake phone after few minutes and check messages
- force phone not to go into sleep (very bad idea, 2h battery life)
- use Cloud To Device API introduced in Froyo, which is somehow similar to Apple's Push Notifications

My current understanding is, that maemo has completely different way to handle this, that is:
- while phone goes to sleep, data connections are kept open. Phone will wake up on any incoming packets, the application will instantly check what is going on and the phone will go to sleep again.

Could someone shed more light on this, please?