Let's look at two deals:
Burns is 26 and signed for one more season at $4M; San Jose gave up significant value for him, despite his injury history. Regehr is 31 and signed for two more seasons at $4M per; Buffalo gave up essentially nothing, but had to take on Ales Kotalik's $3M contract. Why would San Jose make this move? If they had consummated the Regehr deal, they would probably be two wins better today than they are! The Sharks, unfortunately, are not one of the higher revenue teams in the league, and even though they're well-below the salary cap, they couldn't take on any additional salary like Kotalik's if they wanted to avoid an operating deficit.
We are going to start seeing this in a lot of places. Outside of the top 8-10 teams on the revenue side, other teams will have to make due with fewer wins than they could have achieved with a full budget. It was one thing when bad teams didn't spend; it's a whole other issue when a really good team like San Jose doesn't spend a few million dollars that could make them the favorite going into the playoffs.