24 hours later and I finally can type something out, since I found out last night but I was already quite drunk, coincidentally with the buddy who I went to see Dream Theater for the first time with (ToT tour at MSG) back in the day. We dedicated the rest of the night's drinking to DT/MP and listened to the bootleg of that show through ACOS.
This is the first time I've watched a favorite band go through some sort of trauma, every other band that I really listen to either has been disbanded already (classic rock stuff) or hasn't had a lineup change (closest I came was Newsted left Metallica 6-8 months before I became a fan). It hasn't really hit me until tonight though. The last hour and a half or so I've gone through this whole thread, and reading some of the posts here while listening to Jordan's improv piece nearly moved me to tears, and I don't think I could make it through some of the more heartfelt DT songs without getting too emotional.
Between being my absolute favorite band, the holy trinity of I&W, Awake, and SFAM all probably inhabit my top 5 all time albums list, and leading me to the various incarnations of DTF where I've found some of the best friends I have, spent a mind numbing number of hours in conversation with a great group of people, and discovered most of the rest of the music that's filled my ears in the last half a decade or so, Dream Theater has far and away been a huge influence in my life since the first time I put Six Degrees in my cd player and The Glass Prison blew my mind. I have no doubt both Mike Portnoy and the remaining members of Dream Theater will go on to create more great music, that's what they do, and I'll continue to check it all out. That said, even if the new music Dream Theater puts out is fantastic, and better than their recent output (I wasn't one of those "Portnoy is ruining the musical direction of the band people, though I didn't particularly care for good chunks of Train of Thought through Systematic Chaos. I thought BC&SL was a big step in the right direction though), I think anyone who tells him/herself that the experience of being a Dream Theater fan will remain the same is still in denial. In addition to the music, the whole experience of loving Dream Theater has been incredibly rewarding, and it's been so in large part thanks to Mike Portnoy. The rotating setlists, the official bootlegs, directing the DVDs, all the communication with the fans (his forum, Christmas vids etc...), all that done by a man who, as someone earlier in the thread said, worked 25 hours a day for Dream Theater fans. Some of those responsibilities may be taken up by one or more members of the band, but (with all due respect) none of the rest of the guys ever exuded the kind of passion for making Dream Theater as great a band to be a fan of as Mike did, and that's what I think will be missed the most.
Mike, I understand why you had to make the change you did, and I wish you the best in whatever musical endeavors you undertake in the future (more Transatlantic would be nice, hint hint), I'll be along for the ride listening. JP, JR, JLB, and JM, I understand why you felt the need to press on, I look forward to finding out who will be playing drums with you guys in the future and I'm excited to hear what the next album of music you guys put together sounds like.