Heh. No one ever sees the elephant in the room.
The reason you don't see something like an annual pass is that transit authorities love to have the option to raise fares mid-year (even if we never actually see it in practice here...). Those damned annual pass owners couldn't be hit up in that scenario. All this talk about "it becomes too valuable", "mid-year refunds" etc - ask yourselves why you also cannot buy a year's worth of monthly passes in advance. It's not like there's any logistical reason for CT to print up the passes only 10 days before the next month. It's not like they may not offer the pass the next month - the bulk of passes could easily be printed in December for an entire year, and then additional print runs if you see a sudden unexpected spike in demand. No, it's done this way because they want to reserve the right to hike fares at any time.
When you actually *ask* about it, the response inevitably comes down to "we just don't see customer demand" - yeah, even in a system where 70% of your ridership uses passes and the majority of them use a pass each and every month. I'm sure there's no demand just because you specifically don't have 100,000 people calling in to ask that specific question.
Calgary's transit is so commuter focused compared to many other cities that an annual pass is a no-brainer here. Maybe with the electronic cards we'll be able to have automatic monthly "renewals" tied in to a credit card. That'd be handy.
Interestingly enough, I can tell how few of the folks on this forum are heavy transit users whenever I post about the annoyances of being a regular transit user. I'd expect more considering the general pro-transit, anti-car tone we usually see.

I should set up a poll thread sometime.