I use Tcl/Tk at work as well as Perl and a new version (8.5) is just around the corner. The link below describes some of the changes occuring in 8.5.
I also know that the Tcl Core Team will be putting OO hooks into the Tcl core (8.6). It will be its own OO language construct but its overall goal is to allow other OO frameworks to get their hooks into the core by using it. Once in, this will filter into the tcllib packages making them more robust.
Oh, and "Tile", which will make Tk themeable is coming as well.
Some cool stuff...