[Aethaeryn]

Yes. They should have saved the start button and tried to keep familiar concepts that they could then later slowly phase out in future releases.

One way that they could have gradually introduced Metro in a way that would keep familiarity of use to old users and almost total backwards compatibility would have been to replace the desktop with Metro (i.e. the wallpaper and desktop icons). They could have then kept the start menu and panel[1] at the bottom (and perhaps default it to have auto-hide on). They could have even allowed windows to open up over the metro tiles, and then the familiar 'Show Desktop' button on the panel would be how you get back to the full metro screen.

There wouldn't be two modes and they'd still have a very similar appearance to what Windows 8 actually looks like today without having to confuse people used to the old way of doing things. The tablet and mobile version would then not have the start menu and panel, but everything else would look and feel the same.

They could even have implemented it in a similar way to their ancient 'Active Desktop' technology, except fullscreen and without the traditional icons.[2]

[1] I'm using the Linux term here. I really have no clue what they call the bar at the bottom because I haven't used Windows regularly for many years.

[2] http://i.technet.microsoft.com/dynimg/IC193546.gif

[bztzt]

I can definitely see some benefits of keeping the taskbar/panel on screen, but I think they were primarily motivated by the belief that designing the interface around apps being fullscreen would be more attractive to developers. The bottom edge is pretty important screen real estate both for touch (appbar) and mouse (scrollbar, zoom).

[sanjiallblue]

The start menu had to go because Windows 8 is Microsoft's big gamble to jump into the tablet market. A start menu doesn't make much design sense on a tablet or smartphone and they're clearly trying to out-design Apple with Windows 8.