Garmin's nuvi 465T page is up, and they've posted screenshots which will give you hard-working truckers an idea of how the interface will work. First of all, note the squiggly road warning in the lower-left section of the screen above. Tapping it probably brings up a detailed warning screen as seen below.
You can also see that warnings show up in the next turn ahead field in the upper left, below.
And here's the detail screen, warning of a low clearance structure ahead, showing its height.
Here's the truck profile setup screen...
Finally, we have the main menu screen. I don't recall seeing the route option show up on this screen on other nuvis; I just tried and couldn't bring it up on the nuvi 885T that I'm currently testing. Also note the truck icon at the top of the screen, which seems to indicate that you can easily take it out of truck mode for times when you are using the 465T in the family car.