We now know what the title for the Season 5 Opener will be. It will be called Cutie Markless. This was confirmed via a press release for a DVD that includes Show Stoppers, Return of Harmony, and the Season 5 Opener.
Nothing really else was revealed. Like the exact airing date for the opener has remained elusive. But it's something.
From my experience though, it's good when they keep things mainly tight-lipped until the episode airs. It's what made the latter half of Canterlot Wedding as well as the epic DBZ-esque fight in the Season 4 Finale so sweet.