That sounds like a great idea. It is interesting, though, since I do not know anyone with a standalone Tomtom GPS device. The folks I know with standalone GPS devices have Garmin products. I did purchase Garmin Mobile when I used a BlackBerry, since it was cheaper than paying a monthly subscription for Telenav. One of the reasons I picked a Nokia, rather than an HTC Windows phone was for Nokia Maps.
I could see BlackBerry Traffic being a very useful app. It was available when I was still using BlackBerry, but my device memory was too low to use it on my 9700.
It should be a much better app, since it will be developed by a real GPS company. Although I do not know anyone who uses Tomtom, it is a good company from everything I've read.