It was inevitable that this would happen. For Maemo to propagate and compete with Android and Apple, which both have DRM built in, than it would eventually have to adopt DRM too. It won't get support from content providers without it, and cell providers are insistent on having control of the devices on their network. At least Nokia is being pragmatic about it and offering an unsigned mode for the phone operate in. And I hate the term "trusted computing", it's like calling the IRS my personal financial advisor.

Also DRM is usually based in software, so it's adoption shouldn't prevent moving the n900 to Maemo6.