i personally love the 3g on the kindle 3. i am always traveling between school and home and just going around town. i hate having to search for a hot spot to plugin to just to check my mail or search something on the web or read the current news (which i am addicted to).
i also use my kindle in church to look up the passages and search for historical context from different perspectives. and
http://m.blb.org/ is great help for this.
i would never go back from the 3g decision i love it. i probably end up using the web browser more than actually using it to read my textbooks which is why i got it. though still wish that they allowed me to listen to an audio book and surf the web (which i emailed amazon suggesting hoping they add the functionality for that).