Here's what a typical newbie will do when he sees your post: He'll see that you have posted a ton of comments and have been thanked for quite a lot of them. That instantly gives you more credibility than the average poster (you're no longer a troll).
You don't get jedi mind powers, but your words will influence this newbie's decisions because many people have thanked you for the comments you made.

So wait--first you're telling me to keep quiet about what I want to say, then tell me that what I tend to say gets lots of thanks. Uhhhh...

Are you determined on not understanding that your words carry more weight than mine? - and that as a result you might want to consider the consequences of what you post?

I've already said enough. Take from it what you will.

Here--let's add some real substance to this conversation instead. Something that might actually help the Original Poster (OP):

1) Can you identify some other developers who produce commercially viable software on the N900 and make money off of it?
2) How soon can we expect MeeGo devices to turn up and will they have the Ovi store as well?
3) Does the investment of time and resources pay itself off and produce a profit in Maemo?
4) Would you expect that primarily targeting the MeeGo platform would pay off better than targeting Maemo?
5) Would it be easier to port code from one to the other or the other way around? Would there even be a difference? Maybe the whole point is moot? Or would targeting Maemo now cause problems with quickly and cost effectively porting over to MeeGo later?
6) If you want to argue that GTK or QT would make it easily portable between the two, why even ask the question at all? Why not develop it for the Linux desktop and then just just build for Maemo and MeeGo all at the same time NOW?

Mind you, I have no idea about these things myself--so you can now consider me about as daft as a newbie, despite any credentials you see listed in thanks and posts.

OK, so now... Discuss.

Also, if I may bring up another point: Isn't MeeGo possibly going to be running on many devices from multiple manufacturers (at least Nokia and Intel, for now)? Wouldn't that also provide another incentive over targeting Maemo?

If you want to develop for the n900/Maemo, by all means you should use Qt, and look at the ovi store. Both are going to be what gets you the best coverage among not just the n900/Maemo, but ultimately all current and future medium/high-end Nokia devices.

Assuming you develop with multiple platform screen sizes in mind (and this is fairly trivial to do with Qt) you can write an app once and reach many many more users (ie, potential customers) than you could with Android or iPhone.

So basically, develop stuff on Qt and think about platform later?