If Elvis is the cornerstone of the trade from the Broncos end, then the compensation should be about even. I wouldn't expect the Broncos to tag a 1st on onto the trade because of the relative age, and production of both players. The only way this trade would piss me off is if the Broncos coincided a first round pick.
I think our front office will hold out for a second or third, and Elvis making this a good trade. Champ is 35, and in the twilight of his HOF career. He is the kind of player that comes around once every decade, and the Broncos have the opportunity to replace him with a similar generational player on a seven year lease if you assume Revis stays productive as long as Champ. You also put yourself in a situation where you have three of the best corners in league (Chris Harris is hands down the best nickle corner), along with arguably the best pass rusher in the league; that is legendary potential in today's pass happy NFL.
The challenge is replacing the production of Elvis Dumervile with either a veteran, or rookie DE. Given the Brincos defense last fall, you would need a guy who is quick off the edge in a wide 9 or 7 technique. This is where a guy like Cliff Avril, Osi Umenyiora, or Dwight Freeney come in. You also have the opportunity to upgrade the position by acquiring a guy like Michael Bennett who can stop the run, and generated 8 sacks last season. There are definitely short term options available, and some of them might come relatively cheap if the Broncos move early, because it looks like there is going to be a pretty substantial bidding war over Kruger to the tune of 9 million a season.
Then there is the draft, not just any draft either, a big ugly draft loaded with linemen. If my assumption in believing John can get away with only a second in compensation, the Broncos will have the ability to draft a young DE with pass rushing ability as a long term solution to losing Elvis. Couple this prospect with the plethora of aging pass rushers hitting the market this offseason (ie Osi & Freeney) who could be attained at reasonable contracts, and you lost little in letting Elvis go. That is why this trade makes sense, its a matter of forward thinking. You stack the defense for an abbreviated window, while still building for the future by acquiring players at key positions that are about to be voided on your team. John made it very clear when he selected Brock that he was not building this team in 4-5 year windows. That selection gave me the impression that he is thinking about how this team is going to look long term, and acquiring players for both the short and long term to keep it competitive. That is what this trade would indicate, and that's why I like it. I love Doom, but this trade makes too much sense to pass up.