For now, there is Classic Shell which is a free start menu program for Windows 8 which will bring back the Startmenu for free. Classic Shell also can disable the modern tiled user interface, set Windows to boot to desktop, and disable hot corners in 8.
Maybe Microsoft is delaying the Startmenu launch for Windows 8 to get free posts from tech blogs, and forums for Windows 8.
I almost see a post about Windows 8 leaks bringing back the Startmenu every month on many popular blogs. I imagine once the start menu gets released, there would be fewer posts about Windows 8 after a few weeks of the Startmenu release.
Same for me, I been using Classic Shell on Windows 8.1, and it works great.
I think Microsoft is aware that there are many start menu programs for people who want the start menu back. Users can get back the Start menu for free with Classic Shell after they download it from Classic Shell's website which they can easily find by searching the internet with Google, Bing, or Yahoo for Classic Shell, or Startmenu program Windows 8, so Microsoft does not really need to quickly release a Start Menu update for Windows 8 because there are already many free and paid Startmenu programs for people to download from the internet to get the Startmenu back in Windows 8.
I read on a blog that some PC makers like Lenovo are now bundling third-party startmenu programs like Pokki for regular Windows 8 laptop, and desktops PCs.