I know how, you feel, as I felt the same until yesterday, when I decided to buy a N900.

I used a WM5 Mobile before, and it is still working, so I was in no hurry to make a decission.

For me the Sygic publishing their navigation sytem was the last trigger, that made me buy now, as it is one of the four "must have" features I need of my mobile.

1) Sync with Funambol
2) Navigation
3) Radio
4) Graphical Calculator

Additionally, the N900 has a resistive touchscreen. Others would mention that as a con, but for me it is a clear pro.
As with capacitive touchscreens you cannot use your Fingernails for exact pointing.

And yes, as a Linux user, I was thrilled by the Idea, to have a real Linux system on my mobile too.

I am not sure if I will buy any meego mobile. Because no one can say if there ever will be any navigation software. And I guess it will get a capacitive touchscreen too.

So waiting for meego was not an option for me.