Here is a minor enhancement:
The STS installer should configure roo in the STS workspace if the user asks for roo to be installed.
Background:
I'm running STS Version: 2.2.1.200910210131-RELEASE and using the STS to work on a project I created using roo. I edited some field names in a domain class (XX.java). Tha class was generated by a stand-alone (command line) roo - not the one in the STS.) After saving those changes to the domain class, I noticed that a corresponding XX_Roo_JavaBean.aj file did not reflect the changes I made to the XX.java file, which told me roo must not be running. I edited the spring configuration for the workspace, and was surprised to see that no roo was configured. After that, changes I made to XX.java were propagated to XX_Roo_JavaBean.aj by roo.

Bottom line:
I appreciate the flexibility of using alternate versions of roo with the STS, but it would save other users some time if the STS installer set up the roo configuration in case where the user asked for roo to be installed. The roo configuration should default to the roo folder that was installed by the STS installer.

A minor additional suggestion: When configuring the roo installation for the workspace, it would be helpful to provide the user some feedback that the user designated path to a valid roo installation. That is, that you point to the root install directory for roo, not the bin directory. (Again, this is minor, but for new users of STS and roo, positive feedback is very reassuring.)

Keep up the great work!