If this does turn out to be true, I would definitely be excited. However, an announcement for the sequel would be pretty surprising since the first game hasn't even been out for two years yet.
The mention of Unreal Engine 4 is obviously pretty exciting. My only concern with a sequel though is the development staff. It's pretty clear that Mikami might not have much to do with the development of this game, and rumors are floating around that he might be working with Capcom on the Resident Evil 2 remake. All fingers point to John Johanas directing the sequel. While I'm not opposed to him as a director, he needs to stay away from writing and focus solely on directing. Hopefully, stealth is entirely optional and not forced on us like it was in the DLC's.
Aside from that, I'll definitely be watching IGN's coverage of E3 and keep my fingers crossed for an announcement.