Tablets computers running on Google’s Android operating system aren’t doing too well, but they’re not a complete disaster ether.

At least, that’s according to Google’s Mobile Chief, Andy Rubin. “I wouldn’t say (the sales have) completely flopped,” he said during All Things Digital’s AsiaD conference today. “There are more than 6 million Android tablets out there.”

Mashable has the story, which points out that the wording “out there” isn’t quite the same as “sold,” and that’s a stumbling point that Android tablet figures are often hitting. Apple has sold about 40 million iPads, but just how many Android tablets are actually in customers’ hands or just sitting on store shelves is hard to quantify. That 6 million figure Rubin threw out also doesn’t count certain other tablets, like the Nook Color from Barnes & Noble.

Still, 6 million tablets should at least be encouraging, and there are more Android tablets on the horizon that could cause a splash in the market. Google probably isn’t thrilled about possible Amazon success, given what a big competitor the online retailer has become, but Amazon’s upcoming Kindle Fire might have the potential to upgrade the tablet market numbers a bit. The Android-running Fire has Amazon’s Kindle brand to lean on, which gives it some recognition and reliability, and it’s a smaller tablet that doesn’t try to be the iPad, which is also a good way to distinguish a product in a market full of imitators. Plus, there’s the Kindle Fire’s price point of $199 which will undoubtedly entice quite a few buyers who’d rather not play in Apple’s walled garden.

Android tablets have the potential to fill lots of niches that the iPad can’t, given that it’s a single model and at the more expensive end of the spectrum. Right now, unfortunately, tablet makers don’t seem to have a marketing plan that’s not “Make an Android version of Apple’s product,” and that’s really not working out too well. But eventually, one has to figure that, like Amazon, tablet makers will start to establish their own corners of the market.

Future music offerings could change the landscape

Rubin also mentioned the possibility of Google bringing out its own digital music store to compete with Apple’s iTunes, but said that it won’t be just selling songs for 99 cents when Google eventually brings the store out. “It’s not there,” Rubin said, discussing the development of the store. “I feel we are close.”

Just what that means is hard to guess, but Rubin mentioned that while it would compete with similar stores from Apple and Amazon, Google’s offering would be different in some way. “The store will have a little twist – it’ll have a little Google in it.”

Google could definitely stand to increase the number of ways it distributes content to its mobile users, and a music store could potentially be a great addition there. Already, Google offers Google Music, a cloud streaming service that allows users to upload their music to the cloud and stream it anywhere. It already offers free tracks to users, but there’s no way yet to buy new music and bring it into the service.

But Music is still in the beta phase, and one presumes when Google finishes making its store, it’ll move on to being a full-blown service. But with all the cool new things available to Android users thanks to Android 4.0 Ice Cream Sandwich, adding a music store that would bring Google up to speed with Apple and Amazon would be great for mobile customers.