Google Nexus 7, which was unveiled at the I/O conference, was expected to come in the last weeks of July. The company said it will begin shipping from mid-July. While Google is yet to make any official announcement about the launch date of the Nexus 7, retailer Staples Canada has already started taking pre-orders for the tablet listing July 12 through July 17th as shipping dates.

"Pre-order your Google Nexus 7 Tablet to reserve one of these limited quantity tablets. Estimated sku release date is July 23, 2012. Your credit card will be charged at the time of shipment."

While Staples has only the 16GB version of the tablet available for pre-order for $249, both the 16BG and 8GB, $199 versions are available in Google Play.

Meanwhile, a member of XDA Developer's forum, who had reportedly ordered and then attempted to cancel the device, said he had received a reply from Google that said, "At this point it is no longer possible to cancel this preorder. Preorder shipment processing on your order has begun, which means that our shipping provider is moving forward with delivery preparation."

About Staples listing, Google spokesperson said the company is yet to reveal an official release date. "We have only said mid-July so far," Google said.

Meanwhile Amazon is also reportedly gearing up to launch the possible Galaxy Nexus 7 competitor, Amazon's Kindle Fire 2 between July 31 and August 7.

Which tablet are you looking forward to Amazon Kindle Fire 2 or Google Nexus 7?