Not really, I've been monitoring and mine averages 60-70% at 600. I notice a lot of slowdowns and brief non-responsiveness while the CPU is pegged. Why? It 'appears' random, but haven't had the time or energy to mess with finding out.

I don't have a ton installed, a few active widgets and occasionally throw on something from devels. IOW, your usage != others' usage. Mine doesn't sit idle much (unless I'm in the middle of my nightly 3-5 hour nap).

What could possibly go wrong? That's easy, not much else. The question really should be, "what could possibly be more wrong?" As it sits, this thing may as well be a year old looking for a replacement anyway. Seriously. Well, one thing I can say (at least), it has been fairly stable so overclocking may happily take care of that.

I'm always skeptical of overclocking the CPU. A faster CPU alone (esp. small increases) rarely ever means a huge or even noticeable increase in performance. If designed for the 1GHz, then we /should/ notice something, but not knowing much more than superficial, the bus and a device's thermal dynamics will be what struggles. I'm game and have overclocked most anything I can, but lockups tend to increase, reliability drops, heat goes out of bounds causing these issues and longer-term durability problems so the marginal, if any, improvement tends not to be worth it.

I also overclocked my G1, but I couldn't live with the effects - went from rock solid and reliable (assuming I watched memory) to locking up frequently and I (personally) didn't notice any improvement.

BUT, this is Maemo AND the N900 (which I will likely set aside fulltime rather than just using my backup for BT in a couple months for some of the hardware we see in the pipeline) so the biggest question is why the heck not try? People install sketchy apps from devels and muck around with Linux they don't understand and brick the thing all the time anyway. What's the big deal?