Apple has the upper hand? In what way? The Nexus 10 is already on the market and as a device is superior to the iPad 4 in almost every spec. Yes, specs aren't everything, but they matter to some of us more than others. A fully refreshed iPad 5 in March would be smart, but if they wait until fall, I think they'll continue to bleed sales. Lots of Android stuff on the way, and in one country where the iPad has traditionally been popular (Japan), the Nexus 7 is outselling the Mini. The Surface Pro comes out in a few days -- competition is heating up
Yeah it got amazing specs, but Android still is not as mature for tablets as it is for phones.
Why I say Apple has the upper hand?? Because the Nexus 10 is a reaction to the iPad 4. And as such it is only natural that it has to excel in some aspects to draw attention towards it.
Past attempts have focused on lower price with lame results. The Nexus 10 still is cheaper than the iPad, but in no way is a cheap device.
If Apple release a new iPad right away, they start the ever hurting game of catch up. It isn't good for companies, it isn't good for consumers.
Why??
Because the vast majority of people don't want a new device every two months. Either because they can't afford it, or because they don't care.
If the competition is releasing products that are at least comparable to yours in some sort of way, then you are not doing something right. They way to fight that is trough innovation, not by upgrades every 5 months.
In the moment Apple starts caring about competition and starts a catch up war of specs, without innovation, then we are all doomed.
* And by we I mean, people who have a ton of apps in the iOS ecosystem. Because as always another company with a lot of innovation will rise, to get the crown.