tv-out and keyboard+mouse via HEN or bluetooth

But, still, i don't think it (doom, not keyboard+mouse) will ever happen. I must admit that I'm quite uninterested in doom itself, but there are many great mods based on engines (some are not even FPS!), that would be very interesting on N900. Still, no chance due to GPU, I think.

// edit

@don_falcone

I don't know why You think bluetooth sucks much power. Both bluetooth mouse and keyboard got it's own batteries, and while I'm using my bluetooth mouse with N900, I can hardly see (via current monitoring) *any* increase in battery usage. Also, hostmode - while using *one* device, not several via HUB (for example, USB keyboard, and bluetooth mouse), doesn't suck power in any extreme rate.
Just for the record.

As for Doom 3 engine, as I've said, many great games - that would be much more playable on N900, than Your average FPS - are based on doom engine. Even adventure/action mixes, not to mention things like "unofficial Thief". It doesn't mean, that I think it will ever happen, but, it's not the case that there is no point of doing so (in case of it's being achievable)