I guess the question is whether there's anything you'd like to change from your Shift 2.
If not -- if you've tried all the options and decided that the Shift 2 was perfect for your needs -- the Verve 2 looks like a good replacement. Go for it!
Personally, if I had a 4-mile commute each way and was using the bike for primary transportation, I might consider some of these possibilities (but again, it's all a matter of what you find personally appealing):
1. For a commute of that length, I'd definitely want handlebars that aren't flat. North Road would be good, Moustache would be better, Butterfly is a distinct possibility.
2. I'd want somewhat narrower and faster tires, without sacrificing durability. 32 or 35mm width, and slick, but Kevlar-belted. IMO, 45mm is overkill if you're not going off-road. Continental Sport Contact are quite nice. I'd probably want slightly higher gearing, as well.
3. I'd want fenders for sure. Possibly an internally-geared hub, possibly a Hebie chainglider with it, and possibly dynamo-hub lighting.
So, if you're not sure that what you've had in the past is really best for you, you might try some test-rides on bikes with some of these characteristics. If your bike shop is a Trek dealer and you like working with them, you might ask about the Elektra Loft 7i or 7d. Or you might at some point consider upgrading the Verve with new bars or tires.