TSSM Blu-ray did come with a slip cover. The BR released on 4/22 and for about the first month or so, if you purchased a copy it came with a slip cover. A very nice one I might add. But for some reason any copies after that initial batch sold out, do NOT have a slip. I've no idea why. So, if you want one with a slip cover, they're still available but you have to shop around. Some of the independent sellers on Amazon have some copies left, there's also Ebay, maybe Craigslist. But if you order direct from Walmart, Amazon's main distributor, Best Buy, Target, etc. they will all come slip-less.
GotG made my top ten. I've seen it twice. It's just awesome.