The CRTC regulations for digital TV say that the BDU must pass the digital signal on to the end user in the same format and quality in which they receive it, with no degradation.
The current problem is that ExpressVu seems to be skirting the regulation for some 1080i channels via a loophole where they say the conversion from 1080i -> 720p is being done by the broadcaster before it's delivered to Bell.
That could be true in a couple of cases (ex. Global-HD and maybe CTV-HD), but the last time I checked they were still delivering CBC-HD and HDNet to customers in 720p, and there's no way either of those broadcasters are converting their 1080i signal to 720p for ExpressVu.
In short, the regulations are there to protect the viewer from signal degradation, but nobody seems to be holding ExpressVu accountable on the matter 
.
