The xbox is finally profitable so it would be stupid to drop it now. Also Microsoft has made huge strides this gen in terms of gaining market share and popularity. If they continue to do what they are doing now and make sure they don't repeat the mistakes of this gen with the rrod they will become profitable even faster next gen and experience higher levels of profitability.
The 360 and original xbox are two of my favorite consoles of all time so I for one hope they never leave the console race it was hard enough to say goodbye to sega. And besides if Microsoft leaves the console war who is Sony and their loyalists going to hate on? Most people can't hate on Nintendo because most people at one time or another was a Nintendo fan.