Among the Districts hosting the NA's, the two in closest proximity are Long Island Sound and Southern New England, on Narragansett Bay. J/30s from either region can reasonably and inexpensively deliver to the regatta by water, although it seems that more travel north than south. The NA's have been held at the Newport Sailing Center (1981),
Newport YC (1987), Newport NOOD (1997), and twice at
Barrington YC (2000 & 2004). A hurricane nearly canceled the 1991 NA's at Hyannis YC.
To encourage more widespread fleet activity back in the '90s the Gov Board instituted a rotation that has stayed fairly well in place: Long Island, Chesapeake, Southern NE, and Chicago (or most recently the unfortunate attempt at
New Orleans YC in 2005). Thus it would be natural to go back to Narragansett Bay for 2008.
Bristol YC looks to have several active J/30s racing and the facilities to support the event. I say go for it.
Personally I'd pick mid-August, say 8/15-17. CBYRA Race Week over Labor Day weekend is a fairly big draw here in Annapolis. It's also not too early to start thinking about 2009, maybe somewhere off the Atlantic Coast.