I think the Ravens got a bargain. I haven't seen the specifics of the deal, but reportedly it is 5 years for $26 million, not including incentives.
The signing bonus is small enough that any dead money hit after a few years isn't catastrophic if he is released (especially with a June 1st designation).
If all incentives are earned it would be $35 million (and means he is playing very well). That is $5.5 million less than Kruger's deal, and I believe Dumervil is massively more proven and better than Kruger. Plus, Dumervil was cut, not signed as a unrestricted free agent, so that acquisition does not count against compensatory pick calculations, whereas losing Kruger will net us a 4th round pick. Basically we traded Kruger for Dumervil and a 4th round pick and paid less money doing it.
Dumervil led the league in sacks the last time he played in a 3-4 (under DC Mike Nolan, our former DC), with his LB coach being Martindale, who is now our LB coach. I think all signs point to him having a good year.
As for the cap, I am not that worried about that for 2014 or even 2015. We have a much larger than normal dead money total this year due to retirements and a bad deal given to Cundiff (sudden bout of nausea typing that name). Ray Lewis' 2013 dead money = $2.95M, Birk = $1.4M, Cundiff = $1.8M, Boldin = $1.5M...there are others, but these are above and beyond a normal Ravens dead money year.
Flacco's deal won't be that big of a hindrance until 2016. No clue what happens then, but 2014 and 2015 his cap hits are around $14.8M and $14.5M respectively. Webb's cap number goes up as well. It will be tight but there are plenty of options. Cutting Jameel McClain would save millions. Jacoby Jones and Vonta Leach both will not be re-signed, that is $4.9M and $4.3M cap space in 2013, respectively, disappearing with no dead money for 2014. Restructuring/extending Ngata or Suggs is possible. Suggs may even be a 'pay cut or release' situation especially now that we signed Dumervil.
And the new TV deal will boost the cap by decent amount in 2015. The cap isn't that dire, though a little bit of short term mortgaging may have to be done to sign Torrey Smith and Pitta (though Pitta won't be that expensive, and really Torrey might not either). But these deals can be structured creatively so they aren't overly expensive until Ngata and Suggs are counting for much lower towards the cap than they are right now (if they are counting at all).