Eastern Townships

This depends a lot on what your goals are and what you want to see. The Eastern Townships is a mostly rural environment of small towns, ski hills and very little else. That's not to say that there aren't things to do, but mostly it revolves around outdoor recreation (camping, golfing, skiing etc) or in enjoying the quaintess of some of the local towns, going antiquing, that sort of thing. There are some excellent farmer's markets and many opportunities to buy excellent produce, maple products, and cheese.

in the summertime there are agro fairs and some x-games type stuff like mountain bike races at Mt. Orford, and some offroad motocross stuff, typically down around the Knowlton area.

Going across the border from the townships will get you to more of the same, unless you're willing to drive for a while, and so I wouldn't recommend it. if you wanted to cross over into the states for shopping or such then I would recommend that you go down to the highgate sprins crossing and go to Burlington, which is a very nice little city about 1.5 hours away from Montreal. unless you have a special need to be in the states it's likely not worth the trip though.

Honestly, with only 7 days I'd me more inclined to take in more of Montreal and Quebec City than I would be to wander around the farmlands, nice as the area and the people are.

What do you consider worthwhile? If you like small towns, hiking and other outdoors activity there is plenty over the border in the US as well as the Eastern townships so you could use quite a few days. If you're more into a city type places 10 seconds should probably cover it.

I think Magog is a good place to visit as well as Newport and the whole Northeast Kingdom of Vermont over the border but your question is way to vague.

If youre going Toronto-Ottawa-Quebec City-Montreal in 7 days, id skip the Eastern Townships alltogether. Theyre beautiful in their own right, but you will be far too busy exploring the aforementioned cities to worry about spending time in small country towns. As for across the border, the New England states are simply marvellous, but again, you could be pressed for time. You COULD go Montreal-Quebec City via the Eastern Townships, but this is half a day just driving, leaving little time to explore the region. I would save the Eastern Townships and New England for another trip.
Cheers, Andy...

Thanks to all above replies. That gives us an idea of what to expect and maybe we'll now spend most of our time doing Ottawa, Montreal and Quebec. Cheers!