fresh install of F11 x86_64, yields the following:

ahecox@t61 ~ $ touch foo
ahecox@t61 ~ $ aspell -c foo
Error: No word lists can be found for the language "en_US".
ahecox@t61 ~ $ rpm -q aspell 
aspell-0.60.6-5.fc11.x86_64
ahecox@t61 ~ $ sudo yum -y install aspell-en
...
ahecox@t61 ~ $ aspell -c foo
ahecox@t61 ~ $ echo $LANG
en_US.UTF-8

one way or another (via anaconda, rpm deps, whatever), a working version of aspell should be available out of the box.