Here's my 1/2 of cent: Sell MBP, keep iPad.
I think that the MBA '10's are the wave of the Apple future. Bar none, HD's have been the SINGLE point of failure in my macs in the last five years.
The MBP you have now will tumble in value, and certainly is nothing like a "macbook that hooked up with an ipad". I can use my MBA (or any 'book with a SSD) in the car, walk around with it, watch netflix in bed, on the couch, take it anywhere (gonna wrapsol it tonite) without a thought.
Let's hope SSD is as reliable as it might be!
(And in the meantime, Time Machine rocks)
G.