I've been spending some time writing custom live templates. LTs are really one of the exceptionally great features of IDEA in my opinion. They are just a bit hard to use.
1) The way to edit them is absolutely frustrating experience. The LT editor is ok, but what is completely demotivating me to spend time in there is the fact that I have to open three modal windows every time between making a change and testing it out.
I see two solutions: either make the LT editor a non-modal window so that we can hit Apply and switch to the editor to try them out. The other solution would be to have some kind of 'playground' area in the editor dialog where we can type arbitrary code. But that might be more complex actually.
2) I would really like to see a simple way to share both live templates and file templates with the other members of my team. By accident I found out that these templates are stored somewhere on disk in xml files but it would be really nice to have some kind of standard way to export/import them.
Even better would be to include 'mDNS' support in IDEA so that I can simply Share my templates with other people on the same network. Much like I can share my iTunes music or my iPhoto photos. Nobody is doing something like that yet, it would be awesome to have that in IDEA.
3) More standard templates in the distribution - It would be really nice if IDEA came with more live templates than just the very few that are now in Demetra. There are many templates that we could use every day without being very product specific. Like a 'for' template or JUnit templates.
A good example of a product that is doing this is TextMate, the fabulous text editor for OS X. It comes with many many live templates that were created by users.
4) Template community? - I know JetBrains can't hold our hands for everything and I'm really not expecting that. If 2 were solved by the means of some kind of public template repository (maybe even just a simple area on the jetbrains confluence site) then people would be able to share interesting templates.