Some More DREAM Act Numbers: Let's try for a master list of DREAM Act potential votes at the moment. Numbers USA lists the following 18 senators as declared in opposition to this act:

Alabama: Sessions; Shelby
Arizona: Kyl [UPDATE--Maybe not--see below]
Georgia: Chambliss; Isakson
Kansas: Roberts
Kentucky: Bunning; McConnell
Louisiana: Vitter
Mississippi: Lott
Missouri: Bond [UPDATE]
North Carolina: Burr; Dole
Oklahoma: Inhofe
South Carolina: DeMint; Graham
Tennesee: Alexander; Corker
Wyoming: Enzi

Activist group Grassfire.org has been contacting senators, and they say the following are confirmed against the measure (in bold are those not on the NumbersUSA list):

TN Alexander
WY Barasso
KY Bunning
NC Burr
GA Chambliss
OK Coburn
TN Corker
OK Inhofe
GA Isakson
AL Sessions
AL Shelby
LA Vitter

If both these counts are right, there are 20 declared opponents of the DREAM Act--and Martinez (R-FL) says he does not support adding immigration legislation to the DoD bill, so that number might be at 21.
These lists indicate that declared supporters of the DREAM Act might include Brown (D-OH), Bingaman (D-NM), and Bayh (D-IN). Obviously, Durbin (D-IL), a sponsor of this bill, is also a supporter.

UPDATE: Sources are telling me that Thune (R-SD) will also vote against the DREAM Act. So it could be 21 firmly against.
UPDATE: I see that NumbersUSA has dropped Kyl from their committed "No" list: 20 against.
UPDATE 5:35EST: NumbersUSA has added Bond (R-MO) to "No": 21 against.