As already said we are going to have spell checking in GTK+. No more GnomeSpell, GTKSpell, SexySpellEntry, the gedit plugin, all using different libraries for spell checking and with several different problems!
I’m working on the glib side of this project, GSpell will be the low level spell checking library that will be the base of the future GTK+ spell checking stuff. The Mercurial repository is at http://techn.ocracy.org/gspell, the relevant bug is #383706.
GSpell has the same goals of Enchant and shares a lot of code with it. Probably the next version of Enchant will be just a wrapper around GSpell.