I think the media blitz is completely dead. Interleague play as it stands does not receive any pub. If you want to publicize it, one series at a time will allow for more media interest. Assume for this year, the season opened with Houston/White Sox. There could be a lot of hype for such a series, then, down the line, you still have your Cubs/White Sox, Mets/Yanks etc. Run together those series tend to drown each other out (with Mets/Yanks taking most of the pub). If you run them in successive weeks sometime in the middle of the season, however, you'll get a longer media blitz. There's a big difference between "Hey, the Cubs, Sox, Mets, Yanks, Dodgers, Angels ......... are playing today", and "hey, it's Cub/Sox this week", " now it's Mets/Yanks" etc etc. Every now and then throughout the season there will be an interesting interleague series going on (not to mention the interesting divisional matchups) for MLB to promote. I don't doubt that MLB would hesitate on such a plan, they always fail to make the right decision. Usually they have a good idea but then ruin it with the details (WBC). But it can work, and can make the league better.