The four part Magnum Opus storyline from Marvel Comics will jump between Deadpool and Thunderbolts, and promises (according to Marvel) to be the fight of 2009!  The company has sent Major Spoilers a sneak peek of Deadpool #8 that kicks off the battle royale that arrives March 4, 2009.

From Marvel

Get ready for the loudest, craziest and biggest crossover you dare not miss!
Marvel urges retailers to check their orders on Deadpool, Thunderbolts and all Dark Reign tie-ins. Who’s the deadliest in this showdown of Marvel mercenaries – Deadpool or Thunderbolts? Find out when the two clash in “Magnum Opus”!

“MAGNUM OPUS” PART 1
DEADPOOL #8 (JAN092474)
Written by DANIEL WAY
Penciled by PACO MEDINA
Cover by JASON PEARSON
Parental Advisory …$2.99
FOC—2/12/09, On-Sale—3/4/09

“MAGNUM OPUS” PART 2
THUNDERBOLTS #130 (JAN092476)
THUNDERBOLTS #130 LANGLEY VARIANT (JAN092477)
Written by ANDY DIGGLE
Penciled by ROBERTO DE LA TORRE
Cover by FRANCESCO “MATT” MATTINA
Variant Cover by CLINT LANGLEY
Rated T+ …$2.99
FOC—2/26/09, On-Sale—3/18/09

“MAGNUM OPUS” PART 3
DEADPOOL #9 (FEB092520)
Written by DANIEL WAY
Penciled by PACO MEDINA
Cover by JASON PEARSON
Parental Advisory …$2.99
FOC—3/12/09, On-Sale—4/1/09

“MAGNUM OPUS” PART 4
THUNDERBOLTS #131 (FEB092521)
THUNDERBOLTS #131 LANGLEY VARIANT (FEB092522)
Written by ANDY DIGGLE
Penciled by BONG DAZO
Cover by FRANCESCO “MATT” MATTINA
Variant Cover by CLINT LANGLEY
Rated T+ …$2.99
FOC—3/26/09, On-Sale—4/15/09

Note the prices on all of these titles is $2.99.

via Marvel