Hi,
I have a few suggestions for the IDE... they're just small improvements that hopefully are all easy enough to implement, and could make the code editor infinitely better. Some may have been said before, but here they are:
Code Autocompletion
As in MS Visual Studio, fills in vars, functions and provides a call tip (parameters and data types) for any function you may be calling.
(ok, this one might not be so simple)
Line Duplicate
Ctrl+D should duplicate a line... it's simple, but it makes it a lot easier when, for instance, a heap of digitalWrite()s are needed (but a loop would be overcoding it)
Auto close bracket
Opening a bracket should automatically generate a close bracket upon pressing Enter, then move the caret to inside the new code block
Options for general text adjustments
Like Tab Spacing (indenting)... Right now it's about like 2 spaces, it seems... I'm more used to the 4 - 6 spaces of other IDEs, so it could be a good idea to make it into an option.
Ok, that's all I can think right now, if anything else occurs to me I'll come back 
Cheers