The current features (starts with, contains, ends with, etc) are nice, but having actual Regular Expressions would be even better!
If this isn't possible, one great improvement would be to allow for IP Address ranges to be used. For example:
Instead of creating a Processing Rule defined as:
Starts with:
129.32.34.15
129.32.34.16
129.32.34.17
129.32.34.18
129.32.34.19
129.32.34.2
Et cetera.
It'd be much more powerful to define the rule as:
129.32.34.15-255