Why do you think Hilllary had Harold Ikes ask Dean to be his Valentine?
To hazard a guess:
Previously, the real power of the DNC chairman was to be the chief fund-raiser for the party. McCain-Feingold has made that function irrelevant. 527s are now the "where the money is".
Consequently, the Clintons can use Ickes to "make" Dean, buying him off and earning his beholdeness. Meanwhile, Ickes can continue serving them as "their man in the 527 environment", where the real money is.
Presto! One less competitor for Her Heinous on the left.
To camoflage the fact that will back Fowler against Dean?