From what we know so far, I don't think the Noble House rules will be necessary (or even overly useful) for the type of games I was a part of in the past. They seem to bring a strategy element to the game, which in itself I don't want to criticize at all (on the contrary!), but which may not be suitable for all gaming groups/campaign concepts.
The house design process, for example, doesn't seem worth the time and effort if the campaign you want to run consists of a rather short series of events, or if it isn't centered on the PCs' house being in competition with other noble houses, etc.
However, in conjunction with the influence and the promised mass combat rules, this could be a whole different kind of Westerosi experience in addition to the more "conservative" type of gaming I've been doing; some kind of strategy-rpg with less actual roleplaying and more planning (maybe even turn-based) in a grand-scale, long-term campaign. I'd sure love to try something like that. (If only I had some more free time on my hands...