Debian developer Joey Hess made the tasksel change a few days back that makes the GNOME Shell desktop the default in place of Xfce. The decision to go back to the GNOME camp was based upon the accessibility, systemd integration, and other factors mentioned on the Wiki for the Debian desktop requalification for Jessie.
There still though is the chance for change as Hess explains, "Some desired data is not yet available, but at this point I'm around 80% sure that gnome is coming out ahead in the process. This is particularly based on accessibility and to some extent systemd integration... The only single factor that I think could outweigh the above is media size, if there was a strong desire by Debian to see a single CD with a standalone usable desktop. However, the Debian live team doesn't care about fitting on a traditional CD; and while the Debian CD team hasn't made a statement, my impression as a member is that this is not something we care enough about any more to make it a hard blocker on the default desktop."
Other factors include the GNOME community being larger, GNOME 3 having improved a lot, etc. Debian 8.0 Jessie will likely be released next year while the freeze is happening in early November. GNOME 3.14 stable is coming this week and should be fully landed for this next major Debian update.