Hi Dan, yes you are correct, last year Shaw launched a third sat that sits at the same longitude as one of their two existing sats, those of us with the new LNB can view (in Canada) the 100 or so channels around 500 and above, most of the channels are duplicates of the HD channels at 300 to 400.
The new sat is ranged to limit the reception to about 100 miles or so south of the US/Canada border. The two "old" sats haven't changed programming (and I don't think they can be "ranged") and they will be active for a few years (a long period in "technology" time!).
In discussions with Shaw they indicate that I will still be able to receive signals in the US but they won't provide tech support if I'm there.
I believe Shaw is being pressured by interests in the US to stop broadcasting US programming into the US that they don't have agreements to broadcast there, the same as the problem Bell faced. That's one of the reason I'm holding back on the purchase of the Winegard dish for Shaw.
2013 Redwood 36RL, 2011 F-450, Sat Internet, Sat TV