"History" tells us that to break into a segment of the gaming market requires having the right product, at the right time for the correct price. Several companies have attempted to break in but it usually results in massive losses for the company. Currently Microsoft has a very expensive foothold in the home console market and it would be very risky to attempt to enter the handheld market at this time.
Personally, unless you have a fantastic idea for a portable, I think it is foolish to challenge Nintendo in this market; there is little chance that you can produce a higher quality total product (hardware+software) to Nintendo in this market.







