The full list can be found here:
I am, of course, delighted by the news and hopeful for both stories.
As an aside: some of you who know that "Paying It Forward" was published in 2003 might be wondering why it's on the Preliminary Ballot now, and not last year's. The Nebulas, unlike the Hugos, work on a "rolling eligibility" system, so a work has a year from date of publication to acquire the recommendations it needs to make it onto the Preliminary Ballot. "Paying It Forward" appeared in the September 2003 Analog, but didn't get its full complement of recommendations until mid-2004, which is why it shows up on the 2005 ballot.
Also, although the Hugo Administrators considered it a Short Story, both Analog and the Nebula Committee consider it a Novelette, so that's why its under the Best Novelette category. ("Time Ablaze" is under Best Novella.)
Preliminary ballots will be mailed to all Active Members of SFWA, with a final list of nominees to be determined sometime before mid-February, when the final ballot is mailed out.