If we assume that the release schedule (and the development time for each episode) are the same as season 3 then we have a pretty good guideline. The first three episodes will all launch close to 8 weeks apart (since the teams have had time to work on them in advance and they'll be ready to go by the earlier deadline). The next episodes beyond the first three will be more like 12 weeks apart, since the teams in question have had less time to get subsequent batches of episodes finished.
What's the ETA on the next episode? My only real complaint was that this one stopped so abruptly, killing the momentum. I mean, something kind of big happened and then there were no events to back it up. I sort of thought the episode would end with an ongoing invasion event of some kind.