Well it's situational.
Used mine as primary for a very, very long time.
But the time has come for me too, I needed apps for my work and pretty much for my daily life that Maemo cannot provide anymore.
I'm using an LG Leon since last week, which is a 2 years old low-low-lowend Android phone, bought it for like 30 €, and its better in every single way possible, except the keyboard which I miss very much.

N900 is still ok if you don't need any mainstream apps, internet, advanced gps and transportation tools, social crap, and standby time.
As a phone, as an e-mail client, or Skype device, PMP, all of these are still working.

It's still very nice as a Linux toy, but as a smartphone, nowadays it's suffocated by it's hw and the lack of support.
Honestly, since I've got my LG, N900 is on my desk, and I have no task for it. :\