Apologies for the blatent culling.
Yes, in manyways you're right. the CSSU and other OSS that makes full use of the available hardware, massively improves matters.

In many ways, there is still no device like it. No true N900 user wants to lose it. The area that bugs most users is, the dichotomy of the always-online/desktop-in-your-hand philosophy against the way some sites treat N900 users like lesser individuals; for example, browser detection (workaround available) and the flash 10 problem. I suppose these are the reasons one might wish to use another O/S (other than proof of concept).

With browserd now open, there is a greater opportunity to improve the inner workings of microB to HTML5, which might overcome the problem of embedded videos?

@OP: Mobiles & PDAs are an embedded devices, the N900 was designed with/for Maemo5 so being able to use another O/S is a happy coincidence of it being near-full Linux, not the intention of device design. In short, if you prefer another O/S, you'll need to buy a device that includes it.