I wasn't aware there was going to be an upgrade in these speeds in the near future. That's fantastic! I'm already very happy with my broadband 50 50d/l and 3upload but 5upload is just that much better!
I updated from extreme to BB50 yesterday and am getting nowhere advertised speeds. The highest upload has been 2.5 and download the highest has been around 30.
I did the same thing as you in terms of upgrade. I also experienced the exact same problems later that night, with the exact same speeds (the speeds being still the same as my previous high speed internet)
I called up shaw support and they looked into it, and literally all they had to do was flick a switch and boom my speeds were at broadband 50 literally in seconds.
I suggest calling them as it could be something simple as them just "turning it on"
That's what happened to me, I hope your situation is similar to mine. Let us know how your situation goes!
I have BB50 in North Vancouver, and currently only get 3 Mbps.
I was told today by support that the 5 Mbps upload speed for BroadBand 50 never was suppose to be 5 Mbps and that it was an error on their website. I expect to see all the 5Mbps corrected to 3 Mbps in the short term.