I always figured on holding these for five years or maybe a lot longer - be the old prospector who comes to town once or twice a year and dumps a bag of gold on the bar.
'Course if you are going to pay renewals for that long the original cost of the domains matters less. Quality is a good thing.
Times like these the long-term investors sleep right through while the flippers think the world is ending. Wake me if they get down to $10.
As for the predictions - 2008 is a lost year, the world economy is awful and that is no fault of the domain market - LLLL or otherwise. I still say the eventual value of LLLL.coms will be around 1/26 the value of similar LLL.coms. It is an inverse bubble 'till then. Is the value of LLL.coms a bit high? Don't know, but even if it is they will have a much higher equilibrium price as the market continues to evolve.
Short .coms are premiere investments for the mobile web - thought by many to become much bigger than the present day internet. That is almost scary when you think about it. Several times the market size and split mainly between short LLLL.coms and .mobi (if dotmobi is successful).
Other than localized use of cc domains, I don't see a large mobile impact for other extensions - or, beyond existing sites, for longer .coms. If you do not like .mobi (I do like it, but whatever) then short .coms are, big time, where the movement will be.