A leaked document from Microsoft has surfaced which gives a bit of insight into when some of the company's key products will be released. Internet Explorer 10, for example, should be available about halfway through the year based on "historical release cadence" — that is, Microsoft's traditional timeline for releasing new versions of the browser. Meanwhile, Office 15 should launch as a beta around the same time, with the final release due in early 2013. Even Windows Phone is included in the document, though it's hard to glean much — we can expect "future investments" towards the end of the year, while what appears to be a yearly update is due for mid-next year. While these documents provide a general overview of Microsoft's product roadmap, it's important to note that none of the release windows are guaranteed. In fact, Microsoft has admitted as much, telling ZDNet that "this information contains our best estimates and is, in no way, final or definitive."