Saving money is the way to go, imo. Save as much as you can as soon as you can. If you want to spend more just so you can get the latest and greatest, you will be spending a lot of money and switching phones every other month or so, because there is always something "newer" coming out. Its really not worth it playing that game.
I bought the curve on the 2-year...wanted the storm but couldn't wait. Storm came out, and about a year after I got my curve, I decided I really wanted the storm. Found a guy on craigslist who didn't want his storm anymore (actually his wifes storm) and wanted a curve instead. I gave him a $100 and my curve and we switched. I could see yourself doing something similar with the incredible if you wanted. I don't think you will want to, but I could see it. And you still would save money in the long run over buying it outright.
The bigger issue is with carrier. I think the Inc has a big ETF fee if you break contract, so as long as you think you would stay with verizon for the 2 years, I would say get the Inc on the discount and enjoy! Now if vzw has crappy service in your area...well that might be something to consider before you make that leap.