The Cornwall Bypass opened yesterday morning, as a new alignment for PEI's TCH segment. I drove it in both directions earlier today.
The Bypass is signed as the new TCH alignment from the TCH segments west and east of the bypass. TCH signage remains on the -bypassed old route (which I re-drove westbound, and also part eastbound), but my guess is that the work crews will get to its removal soon. Work crews were busy repairing the road, now that it has much less traffic, before winter comes.
Also, the old route is signed at the exits at both ends of the bypass as PE 27. No markers yet on the old route itself, though I think the new signage at both ends is clear enough.
Also, the new bypass has only one interchange in the middle (Cornwall Rd., which isn't a provincial route), and there are no at-grade intersections other than the roundabout at the east end.
No exit numbers. With Saskatchewan to get into exit numbers with the soon-to-open Regina Bypass, that might leave PEI as the only province with no exit numbers.
I took lots of pictures, and plan to post some of them on the AARoads forum in the next few days (probably after I leave PEI for a quick dive into Nova Scotia early tomorrow morning).