The problem was that there wasn't anyone available at a reasonable price.
Boyle was available, but at a $6.5-$7M cap hit, and with the potential for a freeze on the previously rising total cap space looming at the time (now, we are looking at possible reductions over the next few years), the fact that we didn't pick him up may have also kept the screws from getting even tighter.
As far as having at least one winner on your roster, I would argue that the impact of one player is only as much as the other players allow it to be; they have to be willing to accept the positive influence. Also, keep the total statistics in mind:
There are at least 630 players active in the NHL (21 players per team, 30 teams, plus injury call-ups, etc)
The average career of an NHL player is 7 years; most will play for at least two teams over their career
In the last 7 years (excluding lockout), six different teams have won the cup; only a couple of players have played on more than one of those teams.
This means that, by statistics alone, if the players were to be randomly re-distributed, there is a little less than 1/3 chance of any particular team having a player with a ring. To have three teams in a row with players with rings, the odds are small, definitely, at around 2.7%, but not outside random chance (very close to the odds of rolling snake-eyes)
Adjust this further by noting that success attracts success (e.g. Hossa to Detroit.) Also note that one of the three is Detroit, which is simply "evolved" from the team that was winning the cup ten years ago, so there are multiple winners still present. Odds then jump to well over 10%, somewhat akin to getting three heads in a row when flipping a coin.
All this to say that having the actual ring may not be the key component. There are some players who "get it" after playing in the ECF/WCF, some only once they play in the SCF. There are even a select few that seem to get it the moment they step onto the ice for the first time. Sadly, Ottawa seems to have accumulated too many (that means any more than zero) who just don't seem to get it, and perhaps never will.
As an add-on to this, your initial point was that perhaps BM has passed his "Best Before" date, and that it's time to bring in some younger talent, who can keep up. Others have pointed at the Heatley, Spezza, & Fisher contracts as proof.
I would contend that his biggest errors came in mismanaging the coaching hires, and allowing the Emery situation to fester for too long.
The Heatley contract is in line with what he would have gotten on the free market; Heatley chose to tune out once the coach tried to implement a system that was wrong for him. He improved (marginally) once Clouston was coaching. Away from Spezza, he has the potential to be an elite power forward, not just a sniper, and I would expect him to make this transition next year, or to enjoy the view from the end of the bench.
The Spezza contract was also financially in line with market, but had the foresight of delaying the NTC. Murray now has the power to move Spezza. The subtlety of giving a NTC instead of NMC suggests to me that he has gotten pre-approval from Melnyk to send Spezza down to Bingo for a while also, if necessary "for conditioning", and that he has considered the potential for having to waive him (ouch - $$$). Clearly, of the two, Spezza was seen as more expendable early on.
Fisher's contract has openings in the NMC/NTC starting 2011-12. This will potentially be the first or second year of dropping cap space. His play will also potentially lead to an increase in injuries and thus less playing time. Murray has left his options open, to a certain extent, in return for a slightly higher salary now.
Murray started with a team that appeared to be running smoothly, but in fact was on the verge of imploding. He has stabilized whatever core he had, but left as much room to maneuver as possible, meanwhile he has quietly rebuilt a decimated farm system. Sometimes you need to take a few steps backwards before you can resume your forward march.