I would not be surprised if I really like the N900, but find myself looking around for a different platform if Maemo 6's security model proves too closed in practice to do useful things. ("In practice" meaning "when I come to offer the software to other people, who want to run other things too without rebooting").

We'll see. That's a tough one to get right. It looks to me like Maemo's "open source" commitment is many different faces right now - Ovi being so closed, expensive and difficult to participate in (and requiring Apple-style approval), some Nokians and marketing talking about how open it is (i.e. not requiring Apply-style approval - it says so in the videos!), Maemo 6 not sure who it is trying to impress - commercial closed source developers or open source hackers, but commercial open source developers trying to build crossover between communities and commerce could have a harder time on it than on N900.