We got the invites in our inbox! Microsoft will be introducing the next generation of Surface tablets on Monday, September 23, 10:30 a.m. ET (7:30 a.m. PT). Hardware analysts Joel Santo Domingo (@JoelSD)(Opens in a new window) and Brian Westover (@brianatpc(Opens in a new window)) will be covering the event live for PCMag, live-tweeting via our @PCMagLive(Opens in a new window) Twitter feed, which is embedded below.

The Microsoft Surface tablet is wonderful to look at and works well for its intended purposes. But the Windows RT and the Windows 8 version haven’t exactly been flying off the shelves. They work reasonably well as tablets, but the Windows 8 version shines a little brighter as a laptop analogue. The Windows RT version has the benefit of being less expensive, but at launch it was still way too expensive to compete with the iPads and Android tablets of the world. Incompatibility with third-party browsers and millions of traditional x86 Windows programs were other strikes against Windows RT adoption. A price drop or two later, and we’re still at the point where you’re more likely to see a Surface at the Microsoft kiosk in your local mall rather than inside your neighborhood Starbucks.

Rumors abound about what Microsoft might unveil today, including new screen sizes, docking stations, external batteries, and the presence of updated hardware including Tegra 4(Opens in a new window) and fourth-generation Intel Core processors. One rumor that has good traction is a new Type Cover or Touch Cover with a built-in auxiliary battery. We noticed an unexplained set of electrical contacts in the Microsoft Surface with Windows 8 Pro, so perhaps these new batteries will be backwards compatible?

One rumor that’s hard to fathom is Microsoft making a 12-inch version of the Surface to go along with the existing 10.6-inch models and a rumored 7-inch version. While a 7-inch version could attract people who were in the market for an Apple iPad mini, a 12-inch screen would be too close to a 12- or 13-inch ultrabook to make much sense.