Firstly I'd just like to say to the people that write/contribute/manage/maintain GCBasic, its a fantastic program and I wouldnt have learned anything about pic programming without it. I'm sure we all appreciate the amount of time and effort you guys put in to making this what it is.
Few big wishlist items I'd really love to see in GC.
HPWM - ability to select a port so you can use more than just one hardware PWM port
USB support for 18F family - some way of doing usb device enumeration and communication so that PICs can be used for USB/PC interface applications built into GC would be a great feature, since RS232 is now pretty much obsolete on PCs and under Windows 8 quite a lot of USB/RS232 converters dont seem to work properly.
Floating-point maths - Since maths isnt my strongpoint I end up with loads of calculations to maintain accuracy that could be achieved with a single calculation using floating point maths.
I can appreciate that its a huge ask for those features so unlikely but you never know :)