Google has announced 70,000 tablets are now being activated per day:
“[Android is] now notching up some 1.3 million activations a day, which includes around 70,000 tablets ("We were late to them", notes Schmidt) every 24 hours.”
This number doesn't appear to count any non-Google Android tablets like the, B&N Nook, or any of the other Android tablets that don't come with Google Apps (and thus are not activated through Google).
While some regard the tablets number as low, it's only low when compared to phone activations. Comparing the numbers for Android tablets vs. iOS tablets paints a different picture:
“Acknowledging the difference, Schmidt said that the figure is going up — thanks to the success of the Nexus 7. ...
In its Q3 earnings results, Apple reported that it sold 17 million iPads. That breaks down to about 188,889 units a day (using 90 days for the quarter). ”
If these figures hold constant then in a year there will be 25.6M new Android tablets and 68.9M new iOS tablets. That’s in addition to ~10M or more Kindle Fires and Nooks, and is a significant jump over previous estimates (some of which had iPad outselling Android tablets by as much as 30:1).
If Android tablet numbers were to keep increasing on this slope, they would overtake the iPad numbers in a couple of years. But Microsoft’s introduction of the Surface could throw all the numbers out of whack, so it’s hard to predict what will actually happen.