Emacs is awesome, but there are some things that more modern IDEs do that are nice. In Eclipse you can get a list of all calls to a function from the spot where it's defined. I haven't been able to find a way to do that with Emacs. etags works great for jumping to the function definition, but not the other way around.
That's not enough to convert me to a pointy/clicky bloated thing for coding just yet, but at some point, it seems like there will be enough features like that that Emacs - even with a lot of customization - just won't be viable.
If I did move to another editor, at least it would be nice to bring the good parts of Emacs along.