Short answer - for me e NO!
N900 is a perfect small mobile computer, but as a phone- it lacks a lot of functionalities. So, it has his own market nitshe, but that's all.
If you want to use N900 as a primary device- at least for me it is not possible. In the last one year I spent/lost a lot time to find tweaks, to find way how to use it.
It is a device mainly for geeks and it is not finished.

Last coupple of days I spent some hours in investigating Iphone OS and Android OS and found a lot of usefull things in both. But for my puspose at this moment I will choose Android- yes, there are many not solved problems, rooting the devices and etc., but I believe that nowadays Android is much more finished OS for the end users than Maemo/MeeGo is.
So for me I decided- use for one or two years Android, then will choose agaiin- if MeeGo is matured enought in this time- maybe I will use it in the future.
It is a shame for Nokia to have such OS as Maemo for last few years and to not recognize that they can use it! In the last 4 year the top management of Nokia was asleap and did not recognize the market trends and issues. If there was enought time and money spent in Maemo in last 3-4 years I am sure that the market situation will be totally different.
I will keep my N900 because as device it is perfect, but also to be sure not to forget how Nokia pushed out his trustfull clients!
Regards to all Maemo fans!