From what I've read, the CO 200's are ER versions which will be perfect for Asian and South American runs, plus they should be an ideal size for trans-Atlantic, plus southern hops. The oldest of these dates from the year 2000, which is hardly old at all, although by 2010, that will mean they'll be 10 years old, which still isn't bad.
Again, from what I've read, they have the new style 777 interiors, and at least they all have commonality as they come from the same source. Perhaps the 767-200ER's alongside smaller aircraft from Westjet will provide Transat Vacations with the right fleet mix. If they need growth, getting 767-300's or 400's to compliment the 200's shouldn't be a problem around 2010 either, with many airlines upgrading to the A350 and 787's.