I also had my first IP change in, well, many many months earlier this week. I'm now using an IP address in a PPPoE DSL allocation. I sorta suspect they are reusing old DSL allocations for FibreOP as users migrate from DSL -> FibreOP. One must effectively use the allocations you have these days.
As for the speed test as Bell Aliant is becoming a very data oriented company and is heavily pushing FibreOP for everything it would not surprise me if they are establishing new peering partners for routing and also upgrading interconnects to handle more capacity. Both of these would help with speeds, to a certain extent. You will still encounter bottlenecks depending on the end to end routing.