Risk of SLT mirror degradation over medium term?

[bfitzgerald]

I'm more concerned about some issues I've uncovered with the actual SLT mirror (see my thread on imaging helpline)
It might be a rare event, but it's having problems with light at certain angles.

As of yet bar these window shots it's not showing up in day to day shooting.
But my concern is that there are some problems with using a constantly in the way of the image sensor mirror. I suspect that Canon would have certainly looked at this type of design (even a glancing look they did it first) but rejected the idea because there are some compromises with a fixed mirror (not just light loss either)

So longevity is less of a concern, but that highlights one problem I've noted

[shooter]

From what I've heard the mirror is cheap and easy to change yourself