I found out about this new website via an unsolicited email from the editor of Wintertickle Press. This is indeed a commercial site but it does claim to address Ontario Curriculum for teachers. The site is still in its infancy but does start with some interesting content.

In the email from the webmaster, there was a promise for a great deal of content to be developed and published to the site by July.
Presently, there are some intriguing links. A Field Trip Planner lists locations and contacts, a discussion board has been created for educators to discuss the issues of the day, a weekly questionnaire devoted to current issues (supervision time was up when I visited it...), and the promise of free downloadable activities.
If you're bookmarking Ontario reference sites, you should consider this one and monitor it as it matures. It has the potential to become a valuable teacher site.