I have a feeling they are going to hold it back for a late Fall release. There's not much coming down the pipeline for first-party Nintendo releases this year as they had pretty much every franchise release last year, so a holiday title is needed. Plus, more recent Zelda titles seem to be released in this November-ish window, so it's safe to say SS will hold true to this.
I would doubt they would go for an August release (if they do, it would really surprise me) as that's the end of the summer game releases. Some quality titles do release then, but it can almost be seen as a dumping ground for titles that would have been lost in the summer release schedule. November would capitalize on the Christmas release window nicely, and with a very-likely Wii Motion Plus Remote bundle they could sell it as a great all-in-one gift idea.
I think also they will hold August / September for the soft release of the 25th Anniversary Zelda... "item" that we aren't quite sure of what it is. I say this because of the Mario bundle being shipped then. This would mean:
June - OoT 3D
September - 25th Zelda Item
November - SS
It's nicely spaced out so it's more likely fans will less to spend on games won't have to choose between only one of the items.