Have the option to capture parameters from queries
Presumably this would require having the trace enabled and you wouldn't necessarily want to be capturing every parameter on every query so there probably needs to be some logic around choosing what to keep. This would obviously help track down parameter sniffing problems along with other troubleshooting of the exact scenario you are trying to look at.
This is different from the suggestion listed here:
(And that one should also be implemented and would be a valuable time saver)