Didn't know the dollar figure, but that's what I heard too.
http://www.freerepublic.com/focus/f-news/1721646/posts
The DSCC's optimism about winning the Senate is apparently contagious as the DNC is going to pony up an extra $5-10M for the Senate committee, according to sources familiar with the previously reported arrangement between the two campaign orgs.
While the DNC doesn't have $10M to just toss around to another campaign committee, the DNC apparently has decided to go into debt to come up with the extra cash DSCC Chair Chuck Schumer has been pleading for from DNC Chair Howard Dean. The actual amount of the loan the DNC is taking out is not known as the committee holds out hope they can raise nearly everything they need before the election. But a line of credit has been opened.