Found it! It was on the Drum Corps World site
Bleah. It's pretty bad:
Beginning in 2004, amplification of pit instruments and the human voice will be allowed in Drum Corps International shows. The proposal, presented by Youth Education in the Arts director George Hopkins, passed by a 12-8 vote at last weekend's board of director's meeting held in Orlando, FL.
Also beginning in the 2004 season, division II and III corps will have a new minimum show length of eight minutes and 30 seconds. This will allow the corps to spend more time working on segments of the show and should increase the quality of the performances. The proposal passed unanimously, as did a boundary violation clarification. This clarification, which will be effective for the 2003 season, states that performers may stage or drop equipment over the boundary line but may not perform there.
That's not the same as making it a marching band but it sure sounds more like a stage show than a Drum & Bugle Corps. I guess "Blast!" had an affect. Does this mean that Celine Dion is a drum corps now?