Losing Blissey really hurts. But, I also think that the main reason Blissey was good is because of SP (great Garchomp and Blaziken counter, as well as making it impossible to be hand locked). I only run one Uxie in my deck now and rarely use it as is, its not really needed. Trainer lock isn't that big of a deal really. It will hurt more next format since Steelix loses Blissey AND Volkner, but it will keep judge. But, also remember, Gengar SF will be gone....so, while it will hurt, it won't be as bad as it was this year.
I was talking it over with my friend on the long ride back from Regionals. Its unfortunate that it will lose even more cards that aren't being used to help it now that could be used, but there are still some awesome ideas available, some more viable than others. As far as how good the deck will be, 'Toed is right: IF Fire sees a lot of play, it will not see much play. If not, it will be VERY good.