The current series of The Flash ends with #247, arriving in stores tomorrow.
Flash: Rebirth will be a 6-issue 5-issue miniseries written by Geoff Johns with art by Ethan Van Sciver, and is scheduled to start in April 2009. Ethan Van Sciver is drawing it, and has released one panel of preview art (see below).
Flash: Rebirth is centered on Barry Allen, but will “touch on all the other Flashes”—presumably meaning at least Jay, Wally and Bart.
Geoff Johns wants to “make [the Flash] mythology even bigger” in Flash: Rebirth, much like Green Lantern: Rebirth and Sinestro Corps War expanded the Green Lantern mythology. Johns says it “will be very science based, but will also blend in the quasi-science of the Speed Force”
Wally West will be getting a new costume designed by Ethan Van Sciver, and will still be called the Flash.
Update (Jan 19): The solicitation for the first issue is now available, confirming a release date of April 1 and the format: 5 oversized issues, 40 pages each for $3.99 (like Rogues’ Revenge).
Update (Feb 6): DC has released a 5-page preview through New York Comic-Con and Newsarama.
Update (Mar 27): The covers for issue #1 have been revealed.
A new Flash series will almost certainly launch after Flash: Rebirth finishes. DC hasn’t officially announced when, who will write it, who will draw it, or even which Flash will be the star. Geoff Johns has been very strongly hinted, and it’s almost guaranteed that Barry will headline the book. It seems unlikely that they’d go to all the effort to bring him back, do a high-profile mini-series, and relaunch the book, just to keep someone else as the focus.
I think that covers the major issues. There is, of course, lots of speculation. Here’s a quick link to all posts here about Flash: Rebirth.