There are some Windows Mobile 6 smartphones already out, but you may not be in a geographical area where they are available yet. I would imagine you will start to see some by the beginning of the fall semester, most likely earlier.
As far as upgrading goes, it's kinda dicey. Some manufacturers do it, some don't, and sometimes it's possible to force an upgrade on your device if you know enough about IT systems (although you could just as easily destroy your SP and void it's warranty by doing this as well). Some manufacturers have released a list of Windows Mobile 5 smartphones that will be upgraded, but as has happened before, there is no guarantee this will actually occur until they produce the update for download and people are able to successfully install it.
In the world of smartphones it's always best to wait until the last possible moment when you can't possibly wait any longer to get one. The reasons for this are two-fold. 1) New models are always coming out. You could end up buying the "previous" model and then have a new revision or new product in that same line just next week and the one you just bought sees a serious price reduction. 2) Major problems with a model may not be known for at least a few weeks/months after it is introduced. If you pick up a model that just came out it's possible you will end up with a device that has a serious issue. Most of the times this can be fixed by a software upgrade, but there is no guarantee if or when the company will fix it. Also, it is possible that the problem just can't be fixed because it is an essential flaw in the SPs hardware design (such as with the static problem on the Treo600).
