only "more powerfull than normal skills" do not seem very iconic or "sourcery-ish" to me. they are simply uber-skills ... kinda. sometimes not even that.
instead of those "sourcery skills" we could use sourcery points to empower "normal" skill, eg. per point XX% more damage, duration, range, reduction of cooldown, faster casting whatever.
to be honest, that idea also sounds rather boring and/or cheap. but is IMHO still better than some random high damage skills.
and to be really honest: if sourcery points were removed and "sourcery skills" just fine tuned DOS2 would not be worse. the sourcery points system does not add much to the game apart from a little bit more unnecessary complexity
ps.: also see this thread:
http://larian.com/forums/ubbthreads.php?ubb=showflat&Number=597063#Post597063
