I personally don't think any weapon in the game deserves a nerf. My philosophy: If it isn't overpowered or broken to the point where it centralizes gameplay, it doesn't deserve a nerf. An overpowered weapon or game element renders it the only viable option in all situations (think Meta Knight in Super Smash Bros. Brawl). Team Fortress 2 is devoid of any tactic, weapon, or style of play that is unassailable. Consequently, I do not believe Valve should acquiesce to every irrational and jaundiced player with a grudge against something.
Take the Phlogistinator for example. Was it overpowered? No. Was it easily countered? Yes. A Phlog Pyro may have had 99% damage reduction for a second or two, but he was always more vulnerable than one would think. During the taunt, take a few paces away from the Pyro; shoot stickies at his feet; spam him with rockets while outside of his range. These were all efficient methods of handling him, especially given his loss of compression blast. Did any of this matter however? No--Valve went ahead and published this nonsensical nerf anyway just to appease some whiners. This is a bad business model.
I don't think the Phlog needed a nerf, I think there are a lot more guns that needed attention before that got it...I don't personally use it but again there is a lot more wrong. Since I am bored and nobody is around for me to talk to at the moment, I shall elaborate my thoughts.
Enforcer: as I said above, nerf was 100% merited, it centralized spy gameplay...if you were using dead ringer you were an idiot for not using enforcer and that should NEVER be the case with anything.
Pomson: I really don't think the Engineer needs this much utility moreso than he already has...ontop of being able to drain medics retardedly fast..making spies unable to cloak...it can crit and one shot most classes...it has ridiculous range, and of course like most of the lazer stupidity travels thru opposing team. I think most players in this game agree that Pomson is absolutely ridiculous and needs a tonedown on either it's damage, or utility (I'm fine with one or the other, but certainly not both.)
Tomislav: Here's where most of the disagreements will come from. I feel the Tomislav takes the major heavy downside away and is such a ridiculous crutch weapon it isn't even funny. As I've stated numerous times I don't think Heavy as a whole is a hard class to play, and I personally never touch the class - however I must say why the hell would they make a heavy weapon have a silent, almost instant spinup with negligible downsides? Yes the minigun does more damage, however it's not like the Tomislav does atrocious, even from far away it's considerable - it still has ridiculously high DPS in comparison with most other guns.
Most "update weapons" will add something but create a downside and alter the play a bit - those are interesting updates...I will elaborate on what I mean by this...the direct hit changed soldier from spamming at his feet, to trying to direct hit (SO THATS WHY THEY NAMED IT THAT?!)...and at more advanced levels airshot for the minicrits. The Flaregun as it currently is allows pyro to have some range at the downside of making pyros who shotgun harder to kill. My point is the weapons stated above hardly add any downside other than perhaps some damage loss up close, but don't add anything new and interesting to gameplay. Another interesting update weapon was the ubersaw, which encourages the medic to get up close and person to gain his uber instead of just healing his teammates. Huntsman yet again...these are all solid updates as much as some people hate them - they completely alter the classes playstyle (atleast to a degree.) but they add interesting upsides and downsides...Tomislav, Pomson, Enforcer did not do this.
But I really do enjoy Valve listening to feedback, at the end of the day it is a game - and people should be able to play how they wish to play it, but at the same rate it shouldn't force me to use these weapons because I'm an idiot for not doing what the typical person does. I hope this opens some intelligent agreements/disagreements and makes for an interesting discussion on what people feel needs nerfs/buffs/shouldn't be touched before it turns into stupidity.
Edit:
and to a degree (emphasis on the to a degree part) listening to your customers is NEVER a bad idea, particularly when there is a large outcry for/against something with intelligent arguments.