2020 Gamer Gaming from a consumer's eyes

In the console space this answer is obviously no in the short term, that is for sure. However in the mobile gaming space, this may not be so clear. Right now the Nintendo DS series has been selling extremely well and the Sony PSP is doing okay for itself. So there seems to be some life left in that market for now. However, the rise in smartphone sales across the globe may soon start to cut heavily into the sales of stand alone portable gaming units such as the DS/3DS and the PSP.
Evidence that this may be true can be seen with devices such as the iPhone, the Palm Pre and the Nokia smartphones which are all pushing game applications as a feature of their devices. At some point the masses may not see a reason to carry an additional device if they can get gaming on the go with a smartphone.
Big developers and indie developers alike are flocking towards these mobile platforms. The big developers tend to just port some of their larger platform titles while the indie crowd are developing new games that are designed for smartphone's from the ground up.

One obvious example of a large developer pushing into the smartphone space is Electronic Arts. EA is present on many of the platforms I mentioned with ports of their major IPs. Examples of this are showcased with devices such as the Palm Pre Plus and the Nokia N97.
In the case of the Palm Pre Plus you get a 3D accelerated port of Need for Speed on the device, complete with ccelerometer(motion) controls. With the Nokia N97 you get a mobile port of Spore with the device(this is the case with those purchased directly from Nokia. Carrier branded units may vary). EA goes even further to offer even more titles in the applications stores of Apple, Android,Palm, Nokia and more. In these stores you can easily find games such as: The Sims, Need for Speed series, Tetris, Sim City and more.

On the indie scene you can developers who are devoted to mobile only titles. Polarbit is one such developer. They develop titles for the iOS, Android and Symbian. Their titles are all designed with their platform in mind and offer things that the major developers are not yet pushing in the smartphone space. One example would be multiplayer support in all of polarbits games.
So as more and more developers focus on smartphones, it is likely that people will soon see no reason to have any other mobile gaming beyond their smartphones.
On a counterpoint, Sony does have a foot hold in the smartphone world with their Sony Ericsson venture.
However Sony has yet to put out a PlayStation phone, even though one has been rumored for years now.
If neither Nintendo or Sony put out their own smartphone hardware, it is likely the they will end up like Sega and only end up putting out games for the hardware of other companies.