This is an interesting question with no specific answer.
Generally I'd say if your goal is to maximize what you can get for your ipad, then start selling it ASAP since getting the best price may require more time to find the right buyer.
Personally though, I've not been big on getting new versions of Apple stuff right out of the gate. I just don't have the "gotta have it now" bug that I did when I was younger.
Things to ponder:
- Do you tend to get new versions ASAP after release or do you give it a little time for others to find any issues and Apple releases a software update?
- Will you be buying accessories such as screen protection or a case and what would be the cost savings of letting the aftermarket catch up and prices drop vs. paying full price right off the bat? (might be $20-$50 savings depending on several factors?)
- How much less would you get for your ipad a month after 2nd gen release vs. right now?
- What's the value to you of having the ipad on a weekly or monthly basis? $25/mo? $50/mo?
Basically you can take some guesses at how much an upgrade might cost if you sell now vs. sell later, and compare to the value of having the use of the ipad in the interim.
I bought my ipad used via craigslist for a good price not long ago because I'm doing more business travel than previously. I intend to wait and see what the new version brings and then if it seems to be a worthwhile upgrade, I'll likely wait for refurbs to be available.
By then screen protectors and cases should be available for a little less. It may even be that
for me the upgrade isn't worth jumping on given my particular usage/needs since I don't do games much and don't need the ipad to have a camera; the only rumored upgrade that would really get my attention would be a "retina" style screen -- which seems unlikely for now.
Even if I'd be $100 ahead selling now vs later, it's worth that to me to have usage of my ipad for the two to four months before I'd upgrade.
YMMV