I'm still waiting for things that don't exist (in consumer goods):
high-color Eink
long lasting olcd screens
a rollable display using either of the above
micro projectors (picop)
decent looking highly functional wearable display
devices with >= 64Gig solid state hard drives
fast cheap and ubiquitous internet access

Really I'm looking for small form factor devices with big capabilities. I've had laptops and table PCs and they just aren't convenient. I've also had an assortment of hand held computers but they lack too many capabilities. Now though there is a growing convergence between large highly capable mobile computers and small highly portable computers (umpc and so).

My biggest complaints about the new generations of computers are displays (no matter how much resolution you pack in it doesn't make a 2" square screen any easier to read), capacity (Its great to have a > 1Ghz. proc on the go but what good is it with 128M of ram and 8Gig of flash?), and battery life (you are mobile, but only for a few hours until your full sized backlit lcd and 12000 rpm harddrive drain all your power!).

It seems like technology is coming together to solve these problems, but it hasn't coalesced into a purchasable product yet. Even once these technologies mature there remains one prohibiting factor that will keep them from forming a compelling device - the price. Unfortunately my dream device probably wont be affordable (justifiable) for several years at least. I think user input methods are a continuing and unresolved problem with these devices too, but I haven't found a workable solution yet.

In the mean time I think the N800 and its relatives are the best fit between price-point, capability, and portability.