Indeed he knows.
Since it was just announced today, there still aren't too many details, so I don't know of the specifics of what will be going on in terms of his being there, but I'm going to be staying on top of it.
I don't know if there's going to be an "fan package" with him like there was with the SS cast back in October, but either way, I'm not sure if I would take advantage of that this time. I was a complete novice to cons when I went in October, but I went ahead and purchased a $200 fan package that included a photo-op, seating at the Q&A panel and sing-along, and an autograph ticket for each of the guests there . . . but after actually attending, I feel like I probably could have saved myself some money if I just paid for the photo-op, and then just paid for the individual autographs, not to mention there was still plenty of seating at the Q&A panel and I probably could have still gotten in even without paying for that fan package. So, I mean, I don't know what kind of fan package, if any, will be available with Steve, but I suppose if there's a photo-op, I might get that, and then I could probably just pay whatever he charges at his table for an autograph, and possibly any other photos with him.