supposedly this type of scheduling is a "quick fix" or mend to seasons. From an article i read (which i can't really quote since i cant find it) this type of scheduling (where they hold out and then run no stop through the season) is a trick, i guess you could say, that the station pulls to try to get viewers back.
supposedly, despite overwhelming upset at the announcement, fans come to watch the show in january and with the luck of scheduling a show everyweek for months to come, they draw in more and more viewers. Shows have used this technique for a long time and its proved very helpful in reviving shows.
also, it gives the new writers/producers/actors (or whatever is introduced) a chance to plan and develop a better show to successfully run 20 weeks in a row (but i hope its 22, hehe).
personally, i'm a little upset, but there isn't anything we can do about it. i just hope that they are right and it does bost alias's rating and show quality.
just remember to have faith in alias!