While Google says Android devices total 135m, we don't have totals on Android tablets-- until now, as Daring Fireball's John Gruber estimates Android tablets total 1.21m.

How did he achieve such a calculation? Google itself says 0.9% of activated in-use devices are "tablets" (as in having screens 7" or larger). Following Larry Page's announcing that Android devices now total 135m (at Google's quartely analyst call), a bit of mathematics is all that's required.

Compare this to Apple's iPad sales, now totalling 28.73m-- 24x greater than Android tablets, according to Business Insider SAI. 2011 iPad sales alone still outnumber total Android tablet sales 12:1.

The conclusion? Google and its partners need shift tablet gears, if they're to stop Apple's tablet race domination-- and hope for a repeat of Android's smartphone success.

Go More Evidence of Low Sales of Android Tablets (Daring Fireball)

Go iPads Have Outsold Android Tablets 24:1 (Business Insider SAI)

Good Technology reports tablets make 27% of enterprise customers' Q2 2011 mobile devices activations-- with 95% of those tablets bieng iPads.

In fact, iOS devices are becoming enterprise's device of choice in general. The iPhone 4 is Q2 2011's most popular device, while iPad (1 and 2) activations total more than Android smartphone and tablet activations combined. 

Android tablets till have some way to go-- despite the Motorola Xoom and Samsung Galaxy Tab's debut, Good reports Android tablet activations decline by 3.1% in Q2 2011.

Why the difference? Good accounts it to user preference (particularly from "Bring Your Own device" employees) and verticals such as financial services or healthcare deploying large amounts of iPads. 

However, Good forecasts the Apple-Android gap will narrow in tablets, just like it did with smartphones-- but only sometime around 2012.

Go Good Technology Device Activations Report Q2 2011

Will Android device numbers catch up with Apple's? Business Insider suggests they could, following Google's Q2 2011 earnings call.

Current Android devices total at around 130m-- with activations reaching 550000 daily, up from May's 400000.

This is above daily Apple iOS device activations, currently numbering 325000 iPhones and iPads daily.

In conclusion? Simply put, Android is "completely poised to catch up" to iOS, should Google maintain such growth, according to Business Insider.

Go Android Will Beat Out iOS Before You Know It (Business Insider)

Go Google Announces Q2 2011 Financial Results

The IDC reports WW tablet sales are slowing down-- with unit shipments for Q1 2011 reaching 7.2m, a 28% decline from Q4 2010.

Such a decline follows seasonal trends typical to more mature CE and computing categories. The WW eReader market also feels similar seasonality, with shipments going through such a similar decline and reaching 3.3m units.

The eReader market also shows Y-o-Y growth of 105% in Q1 2011 (Y-o-Y growth figures for tablets are not yet available).

The analyst still predicts growth for both markets' 2011-- with shipments forecasts reaching 53.5m for tablets and 16.2m for eReaders (a 24% increase over 2010).

Apple's tablets continue dominating the market, even if IDC decribe Apple's Q1 2011 shipments as "well below expectations". Other vendors find the quest for market acceptance more difficult, even if the market share for Android-based devices grows to 34% (an increase of 8.2% from Q4 2011).

When it comes to eReaders, Barnes & Nobles' Nook beats the Amazon Kindle for the first time, no doubt thanks to its colour screen.

Go IDC Worldwide Quarterly Media Tablet and eReader Tracker