N900 is a great tool. I have a Blackberry and apart from quicker mail response (the N900 is quite slow) it really has a much deeper interface and useability.
Meego could help in creating a faster UI and much better mail integration and the new BB Torch has a 5mp camera, which this had a year ago.
Its still current and active, Nokia is slow and nowhere near as bad as Vodafone who have locked out upgrades etc.
I'm not a Nokia fan at all but the N900 has a lot going for it.