Things started slowly last year with the launch of the Honeycomb version of Android for tablets, in part because of Google – they released it half-baked and in a hurry, and they didn't take the importance of 3rd party tablet optimized apps seriously enough (I'd say they still don't) – and in part because of manufacturers like Motorola and HTC, who have tried to enter the market with insanely expensive tablets – all more expensive than the iPad at the time.
That's no way to beat Apple. Until you have a powerful enough ecosystem, you can't try to sell your device at a higher price than value, and you'll have a hard time selling the device even at the same price. Why? Because the app ecosystem offers value, and until the Android tablets have that value, they can't really be priced the same.
But more inexpensive tablets are starting to gain market share, and are a small distance away from take half of the tablet market share from iPad. A little more than a year ago the iPad had 95% of the tablet market. Today it only has 55% according to the latest reports. The Android tablets reached 42% market share from only 12% six months ago, and they keep gaining market share at the expense of iPad. That doesn't necessarily mean the iPad is selling less and less, but just like in the smartphone market, the Android tablets are selling much faster, so they are taking much more market share than the iPad.
Things are turning around for Android tablets, but it's hardly an easily won battle. Right now I'd say Android tablets are still fighting an uphill battle, mostly because Google still refuses to promote tablet optimized apps by going aggressively after developers and getting them to do it, and by separating the Play Store in an obvious way into smartphone apps and tablet apps.
At the very least they should give the devs who have tablet optimized apps like some sort of badge of honor next to their logo, so it's obvious to everyone, and they could also allow you to check an "Sort by tablet apps" option in the market. There are really a ton of ways they could promote tablet optimized apps. They just need to acknowledge the problem and do it.