After some consideration I decided to give the Rogue a shot. He's now sitting at level 47 so I still have quite a ways to go before he'll be 80, let alone raid worthy but I'm finding the leveling experience to be pleasurable (excluding the quest bracket holes I've mentioned previously). Thus far the downtime I was somewhat worried about hasn't occured though I do have to occasionally sit and eat. Its far enough in between that its hardly noticable thus far so I'm actually looking forward to seeing how much better this experience will get.
Before I got too far into my leveling I did a bit of reading and took the advice from a great many of them in deciding to level as combat. I didn't have enough Emblems of Heroism left to buy both the Dagger and the Sword for him, so I bought the Dagger for his off-hand and have been buying a new main-hand sword every 5-10 levels. My current sword (Bloodrazor) should last me until Outlands when I'll be able to pick up something better fairly quickly. And I've put Firey enchants on both for a little extra DPS boost.
As with the other characters I've recently leveling I'm really looking forward to getting to Outlands where I can do some real analysis of how easy things are against what it was like with my DK. That isn't my intention in this whole exercise of course, but it does give one a sense of perspective when taking part in various conversations about different classes--something I think a lot of people lack.
My goal isn't to replace my Death Knight as my main toon, but to find another class I am truly happy with that I can do things with when I'm not raiding. Its not that I can't do things with my DK like run Heroics or bag achievements, but having another class to putz around on whenever I don't feel like playing the DK is what I'm really looking for. I'd also like to be able to raid with this second character as well, catching the occasional Naax or Ulduar when possible. Unfortunately I just haven't found that second class that I am completely happy with yet, though I'm really hoping I am with the Rogue.