I LOVE this place.
1) Awesome location at Phillips Place
2) Great for a SMALL group of girlfriends or on a date-- tables at D&D are always packed and it's not really a kind of place where standing around is cool/comfortable so get there early and stake out your spot!
3) I used to have really good sushi here but as I mentioned in my Nikko review, I think the sushi chef moved to Roosters. We used to sit at the bar hang out with the sushi makers and bartenders (winetenders?) and get special sushi made for us-- one time a flamer was involved! AWESOME.
4) People are so friendly! You will definitely make friends if you sit at the bar
5) Kind of a nice-dress place. Not fancy, but as Eric K. said, a little bit dressed up will be better than tshirt and jeans. Guys- khakis usually, girls- nice summer dresses or jeans, heels, and pretty tops.
6) Oh yes the wine-- it's good. You just keep drinking and drinking happily. Wine flights are okay...I prefer just picking one thing to drink, and then maybe trying something else afterwards. Flights are always popular though. It's cool that you can just buy a whole bottle there at retail price and they'll serve it to you, no corkage fee.
Definitely go. I bet the outside tables are nice when it's a pretty evening, but I usually like to sit inside. I wish they had D&D Wine Bar in other locations!!