If you don't want to lug camera gear on flights, find a new hobby
Even the smaller digital camera's end up requiring one to lug a bunch of STUFF. Camera, battery charger, batteries, housing, cables, laptop or some way to move the files off a the media, strobes, sync cords, controllers, trey, additional lenses, media.... the list goes on.
For me I'm kinda looking forward to the DSLR even if it's bigger because I carry my DSLR anyway
You''ve got good advice on the trade-off's of DSLR vs. PnS.
I think what needs to drive your decision other than all that stuff one must carry around
are your goals with the photography? If your goal is to put some web photo's up, and an occasional 8x10 print, then the PnS route maybe a good idea. If you aspire to get published, sell prints, make enlargements beyond 8x10 than the DSLR is the road to take.
As for worrying about technology outdating gear, DSLR's and PnS's are now at a point where they are good enough to get a decade of service (in the case of the well built DSLR) or more. I've had my D1x for three years. Is there better technology out there.. sure... does it continue to take excellent photo's.. absolutely. I'm getting a D200 in the near future, and the D1x will be my backup. Just because something new comes along does NOT mean that what you were using becomes somehow less usable.
I would however avoid the 5050 for one reason alone, and that is because it's been discontinued for long enough that it could become difficult to replace, and even repair parts may become hard to find, and expensive. I suppose if you can pick on up cheap with a housing then go for it. But if not, consider the newer models. They have better focus systems, more mpix, better noise filters, and if you flood one, you can get a replacement easily.
Unfortunately manufactures are eliminating RAW in most PnS camera's which IMO is a big mistake....I mean the photo is shot in RAW, so it's available, why not make it available to the user. RAW is one of my deal breakers for UW shooting especially. Color correcting UW RAW files is a painless quick process, and that is much less true with JPG's from my experience.