Edit: Click the link for full size map - http://i56.tinypic.com/2dhtf5z.png
The OLP has nominated mostly incumbants to start with, focusing on mid-town Toronto, the outer suburbs, Southwestern Ontario, and Northern Ontario. The Liberals are being tactical in unheld ridings with either a nominated candidate, or an active nomination going on. Liberals have candidates in Halton and Lanark-Frontenac-Lennox & Addington, which were the 2 ridings the Liberals came closest to snatching from the PC's in 2007, Thornhill was only lost by 3.6% , Cambridge and Burlington were only lost by 7.6% and 3.5% respectively and have retiring PC incumbents, and while Bruce-Grey-Owen Sound is a bit of a longer shot, it too has a retiring PC MPP.
Liberals have active nomination processes in at least 2 ridings with retiring incumbants that I can identify, with 3 candidates going for the prize in Stormont-Dundas-South Glengary, and at least Nancy Fonseca has declared in Mississauga East-Cooksville.
I'll post the progress of the other parties over the next few days.