I recommend proceeding with caution, and executing small "baby step" nerfs if nerfs are to be forthcoming. Especially since there were recent nerfs to carriers in Entrenchment (which will need some play-testing before anything futher is done?).
This is coming from a guy who just got beat AGAIN (just now) on multiplayer by what seemed to me to be another very mediocre opponent, again with the restriction that I would not build carriers. He of course built quite a bit of them. I have discovered that I simply cannot counter a mixed fleet that has carriers if I do not build carriers of my own (and sometimes even if I do).
I sent a bunch (I mean a BUNCH) of lf to deal with his carriers - 3 to 1 ratio of lf to carriers (when he had 10 carriers in the beginning of our clashes, I sent over 30 lf). When the lf hit his grav well I shift-clicked on all his carriers. He did not kite the grav well at all (just let his carriers sit there), but all my waves of lf always died, and they never killed many carriers that I saw. Why? Because he started mixing in lrf. At first I just proceeded with my strat (lf spam), reasoning that I'd lose some lf to lrf, but at least I should waste some carriers in the process. But his lrf took down my lf way faster than my lf could take down his carriers. Eventually I tried building a few carriers (got up to 7 at once point) to try to counter his lrf, but it wasn't possible. Also built my own lrf to counter his lrf, but my lrf died to his fighters, and I'm guessing his own lrf. Also ended up building some significant flak at some point, but by then he had heavy cruisers and God knows what else, so....
If more balancing is forthcoming, a good idea might be to look into balancing lf killing carriers around how easily lrf kill lf. Try to match the time it takes for the "optimum ratio" of lf to kill carriers around the time it takes an "optimum ratio" of lrf to kill lf. It's an idea, anyway. At least that way your lf at the grav well has a chance to kill carriers at the same rate they are dying to lrf (all things being equal, that is).
Personally, I am through with making any suggestions whatsoever that carriers be nerfed because after this last test game, I have honestly concluded that I suck (Cykur and Howthe? have both stated definitively how to kill carries with lf, and I can't do it. They don't have problems doing it - I do. Therefore, I suck.). And since I suck, I don't want *ANY* balance changes occuring over my suckiness. So take my commentary here (and from now on) not as any personal opinion that carriers should be nerfed (or other things buffed against them), but rather... if adjustments are to be made, proceed with caution, look into balancing around the time it takes other counters to counter what they are countering, etc.
On the other hand, I retain the right to protest against any buffing for the siege frigs, as one poster on this thread suggested. I retain this right because it isn't an issue of my sucking against them, neither in tactics, strategy, or micro - I DON'T (otherwise, I WOULD shut up). Rather, it is simply an issue of "gameplay mechanic." Yes, I can counter you sending siege frigs against my planets - I will just park fleets at all my worlds, or I will just do the same thing to you. The problem is, that just makes for a sucky game. Defenses are piss poor in this game - too sucky to be relied on to protect against siege frigs. No amount of turrets will protect - you will just go around them. Hanger bays were ineffective back when siege frigs had diamond-plated armor - you couldn't build enough of them to protect. If siege frigates are rebuffed it will be cost-prohibitive to ring every planet with hangers, even IF that would be effective anyway. Finally, in Entrenchment the only SB that can protect against siege frigs is the vasari one because it moves. The siege frigs will just go around any other SB. In short, don't buff siege frigs, but do whatever you want to carriers because I no longer consider myself as having any say-so in that.