Recall that the original Xbox ran an operating system based on Windows NT, and it's not like you could boot up Excel on it. The same situation applies here. WIth any luck, some of the core foundations and tools used by developers to make applications for Windows will carry over with little change, making developers' lives easier, but that's about all that matters. We'd be surprised if the common Windows 8 core was given more than a single brief mention on Tuesday, if it's mentioned at all.
Price and release date
Microsoft won't say; it's too early. We will certainly hear a vague release date like "in time for the Holiday season", with more specifcs about price and release date to come later. Perhaps at E3 in June, or even later. When the price is finally announced, we expect Microsoft to lessen the sticker shock by offering a subsidized pricing option: buy two years of Xbox Live Gold at a slightly inflated price, get the new Xbox for a couple hundred bucks less.
May 21 is only the beginning
Similar to the Playstation 4 event in February, Microsoft will give us the big picture, and leave out a lot of important details. It might even follow Sony's lead and refuse to show us what the actual box looks like, saving that for a later date. We'll hear more in June at E3, and even more after that.
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