Gaming on pc's has always been plagued by "Is it fast enough"
You think that's a plague on the pc market?? lol, Most games are funded by venture capitalists, They look into all aspects of a product not just the now but the future and sideways investment as well. These capitalists often have high stakes in other markets other than games.
This is a reasonable example.
Capitalist invests in game, They force the developers to push the graphics to a point where it forces certain products from the playable table. They then invest in the graphics card companies who are going to benefit from increased sales. Once those graphics cards start to sell they sell off stock from the graphics card companies and reel in the royalties from the game.
Provided your hardware is current. ~(less than 2 years old). Then you should be able to expect your system to play most current titles on the lowest settings. Older CPU's GPU's can be pushed from the table, as too can integrated graphics.
This is where your laptop argument fails. Most consumers fail to buy a laptop with a better GPU. Gaming was never intended to be done on that system. The same spec machine with a discrete GPU can and probably does play the title without a problem. This falls down to consumer awareness, and manufacturer advertising.
Back to tablets, A tablet ATM is capable in terms of CPU/GPU of playing skyrim. These tablets are powerful, and expensive. As we are aware technology will always filter into lower tiers, and smaller form factors.
Tablets do not have to compete with desktops. The desktop will always win. However, a tablet that can produce decent frame rates, and offer similar eye candy to a console is always going to be a winner.
The other nail in the coffin of the "is it fast enough" comment is consoles. Consoles limit and impair Moores law. In fact games have not developed since the XBox 360 came out. The "is it fast enough" arguments is now is it a bad port.
Tablets firmly sit within a Moores law model. They should increase in power with a component equal to the desktop market. Added into that in a market where consoles are not a driving force in games development we will see a rise of the old " is it powerful enough" and this is where we should be. Moores law is what keeps your pc fresh and powerful, without the model you'd still be using a 386x86 playing chess master.
The same model is also responsible for pushing hardware, And making sure new hardware eventually becomes old hardware. In a capitalist system without the drive and incentive to invest we the consumers miss out on having new better fast improvements to our gear. granted the model can go out of line and we can see our gear become obsolete faster than it should. But again the capitalists try and moderate things to a level where a products gets the lifespan to warrant a decent profit return. A console fails again here as once the older tech inside them becomes obsolete you have no means or reinventing your market or driving it.
Gaming tablets are very very promising. And the marketing model I expect we will see will be the demise of the console.