Microsoft fans are all aflutter at the news that the technology giant has sent a media invitation out touting a big announcement for Monday, June 18. With the company set to release its PC and tablet Windows 8 system later this year, the speculation is that Microsoft is planning to introduce new tablets.

The entertainment site reported than an unnamed “individual with knowledge of the company” has said Microsoft is introducing its own Windows RT — that’s the version of Windows 8 for tablet computers — device at the event with the implication that the slate will take on Apple’s iPad.

Hewlett-Packard and Samsung are already expected to hit the market with their own Windows RT tablets, but this is the first indication that Microsoft is going into hardware tablet production itself.

Analysts have said that while the iPad has the clear lead in the tablet market, it’s still far to early to count Microsoft out of the game, particularly as more businesses adopt tablet computing. The Redmond, Wash.-based company has a strong history of doing well with businesses and knows just how to market to that consumer.

TheWrap report said that its source reported the new tablet will be running on an ARM microprocessor, as is expected of RT tablets.

Another interesting theory about what Microsoft may have planned comes from ZDNet’s Mary Jo Foley, who put forth the idea that the tablet might not be a Windows tablet, but rather a Windows Phone reader that’s more like the Kindle Fire than a full-on tablet.

While conceding that this is a “bunch of ‘what ifs’ at this point,” Foley suggests that the theoretical reader could be based on Windows Phone, not Windows, and would have the video and music capabilities, hence the decision to have the event in L.A. She pointed out that the settlement between Microsoft and Barnes and Noble mentioned Windows Phone a lot.

The L.A. location has also given rise to theories that the announcement will have to do with Microsoft’s main push into the entertainment space — the Xbox. The company recently announced that its Xbox will be adding “SmartGlass,” a feature that will let users watch video from Xbox Live on almost any mobile device.

The event is not expected to be related to the reports that Microsoft is acquiring the social media service Yammer, a deal rumored to be worth $1 billion. Yammer, which was founded in 2008, is used by thousands of companies to add social messaging and networking tools for business use.

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