I think it's entirely possible that it will, but that we really need to see the full details of the nerfs before speculating too much. The blue post said "To achieve these goals, we’ll be toning down the difficulty of both normal and Heroic raids through hotfixes in the coming weeks. In general, we plan to reduce health and damage of all raid bosses in both normal and Heroic Firelands by around the same percentage we brought difficulty down for the original Cataclysm raids when Rage of the Firelands (patch 4.2) was released." They haven't explicitly stated that the full nerfs will be applied, all in one go, and to all difficulties from next week. That might happen, or it might be staged over 'the coming weeks'.
The way I understand it, the conventional wisdom for progression goes roughly like this:
Next: Rhyolith / Staghelm / Alysrazor
Then: Beth'tilac / Baleroc
Proper hard: Ragnaros
Obviously it's very difficult to give absolute X > Y and you can argue whether individual bosses are plus or minus one, different raid groups have different strengths etc. 25 man is a bit different, with Beth'tilac being slightly harder in 10 man due to the way the encounter stretches your raid comp.
I'm going to guess that Beth'tilac will become a lot more accessible. It doesn't seem right that one of the first bosses you do in the normal mode, and one which doesn't reward tier pieces, has ended up at the tougher end of the scale. Also the nature of fight is very much that of a dps race - if you can keep up with the pace of the add spawns in phase 1, if you can beat the soft enrage in phase 2. Alysrazor might be similar for the same reasons, although I suspect that any group that can't avoid fire will continue to struggle with it.
Edit: note though, that I'm in a similar position to you progression wise, so I really am just speculating.