So far I have released two alphas for Sage 2.10, which can be found in the usual place, i.e. here. Note that there is already an alpha2 directory which contains all so far merged patches and updated spkgs for the next milestone. That way you can easily catch up to my current state. It also enables you to upgrade by downloading the spkgs and dropping them in and downloading the patches and bundles and applying them. Sometimes the order matters, so keeping an eye on the trac timeline helps.
I am not very happy with the progress on 2.10 so far because I ended up auditing the whole test suite with valgrind again and ended up finding three issues that ought to be fixed sooner rather than later. One of them (#1739) has already been fixed, the other two I hadn't even been entered into trac yet. I also build one of the alphas on an Itanium with the tool chain from hell in order to track down a PolyBoRi issue, but I struck out on that one after about a day and a half.
After all this frustration and hair pulling I am finally back to merging and fixing issues I can get done in a reasonable amount of time. But while I do that I will rebuild all of Sage 2.10.alpha2 (once it is out in a little while) with a ucs4 enabled python. The complete rebuild is needed since all python components need to be recompiled and that is only possible if we artificially bump all version numbers of the python related spkgs. We need to do that for the upgrade path anyway, but to experiment a complete rebuild is the easier way. If a ucs4 enabled python works and we have upgraded all the components we plan for Sage 2.10 I will end up scanning all the packages and artificially bump all non-upgraded python dependent spkgs.
You should have gotten the impression by now that 2.10 is more than 3 days away from being released. My current guesstimate is about a week from now, which taken into consideration that many people were at the AMS meeting and the holiday fallout for people to catch up on isn't too bad for a new major release with that many changes compared to 2.9.