The ACPA people claim that you make 70% of your best three year's salary. Take it for what it's worth. But I think everyone is missing the big picture. I don't know many places where you can retire with a pension of 100k/yr. plus. At least not in aviation in the great white north. You also have to consider that in your last few years of service, your salary has been close if not more than 200k per year probably allowing you to build a nice little nestegg. And the few years prior to that you were probably making over 100k a yr. too. You get the idea. If you're looking for a get rich quick scheme, you're in the wrong part of the world.
29chev. If I'm not mistaken, the company gives you only a couple of chances at coming back. They won't wait forever. I think most LOA's will be coming back shortly.
On the question of the 340's, I haven't heard anything. But stay tuned next month for a possible announcement on the 777.