It's crazy because I thought for sure it did. Was using firefox for a bit and got used to one, and then opened microb to post something and no spell checker.
Checked just about everywhere. Only thing that really comes up is old stuff (prior n900).
No idea, if there is one then it have to be through add-on. Otherwise Nokia has to implementing it inside microB. Yes it would be handy but I don't see anything coming yet.