One of the reasons we’ve decided to jump into this CAS process at this point in time is that the new interface is far more student-friendly. We were loath to start with a CAS when the learning curve would be so great. While I know that some would say that the TI is a possibility, it’s short-sighted; no one uses the TI software/handhelds beyond highschool. And the hand-helds are a button-intensive, small screen mess. It’s a toss-up between Maple and Mathematica – and we have an existing relationship with Maple (it’s HQ is down the road an hour).
The interface is now far more point & click 
with no (okay, few) arcane (to students) commands and it describes the step that has been performs.
Graphing is a lot easier (you can drag an expression onto a grid and it graphs!) and parameters can be automated with a click.
That, of course, is the easy part done. Now, the hard part:
- what questions do we ask to develop understanding, concepts, algorithms?
- how do we encourage exploration over presentation?
- how do we avoid an emphasis on calculation/algorithm/button pushing? This can’t be just “better worksheets through CAS”
- how do we make the link between paper-pencil and CAS techniques?
- how do we strength understanding of equivalence (since CAS’ representations differ)?
- how do we deal with the time factor? (student-centred takes more time)?
- are our teachers ready to deal with the mathematical conversation that will/should occur?
