The forecast for peak blossoms is March 26-30, so I think you have a good chance of getting some good shots. My picture in this post was definitely after petals had been falling for a couple days. As far as lens choice goes, your 17-55 will be great. There may be a couple of creative shots you could try with a wider lens, but honestly none of mine were keepers. That being said, I'll tell you that some of the monuments are fun to shoot with a really wide lens...like standing in front of Abe or under the dome of the Jefferson Memorial.
Out of curiosity, I had a search for conferences with those dates. Fruit fly genetics? Who knew?! EDIT: I should say, "Who knew there was a conference for this?". I've long known the species genetics were studied.
If you are interested in meeting up, I'm happy to play photo guide over the weekend.