Hmmmm... A hybrid seems to be a good option now with the tax cuts. But the main concern would be maintenance. Prius and Insight are stand alone models. I can safely assume it would be difficult to find parts compatible with both. And the Hybrid system in the Prius is very complexed (as oppose to the mild IMA system in the Honda), not sure if there are many garages which are well versed with the system. (only place I can think of is the agents)
Also the car will be 3 years old anyway when it comes to SL. So that's 3 years of the 8 year/160,0000km warranty.(not that it is a valid warranty anyway as it's not from the agent) To replace the battery pack, from what I understand will cost around $6000.00 (US). The second hand value will be a concern, with cost associated with the battery pack. And will the battery packs compatible with the MKII be available in another 6 to 7 years? So there is a lot of ambiguity around the viability around Hybrids in SL.
I myself prefer the Honda Civic Hybrid. It will cost almost the same but will suffer in fuel economy. But on the other hand it will have most parts common with the gasoline Civic, also it's a less complicated system than Prius (less things to go wrong)and finally I believe the IMA and the battery pack can be taken out and be replaced with a 1.8l R18 if it is required.