I think Apple must have had a pretty big inventory of the first MBA to still have them and still dropping the price. I don't think the resale price will be "pretty good" or even close, even at the discounted price. At the rate its dropping, in a few months it may only be $799 for a refurbished version one MBA from Apple.
I owned a first version MBA, which I bought for $1799 the week it was available and sold it for $1650 the week before the second version was introduced (I got really lucky). It wasn't fast but was fun. The second version MBA really makes the first version obsolete. At $2499, the second MBA is a better value than a first version at $500. A lot of netbooks sell for $300 to $400, and that is all the first version MBA is... a netbook.
The second MBA is a real MacBook in super-portable form. The SATA drive, the 45 NM Penryn CPU, and the Nvidia graphics are all very worthy and make the new MBA the coolest Notebook on the planet!
If you want a netbook, (at $999) the MBA v1 is there for you. However, if you want a capable Mac, buy the MBA v2. Just my opinion, not meant to be a hate post about MBA v1.