As Rumors has previously reported, we expect an entirely new family of iDevices to be shipping by the end of the summer — and although expectations for an announcement of new 2009 iPhones are running high today, the actual shipping date of those new phones is most likely at least a few (3-4?) weeks in the future.

We also believe that at least one other group of iDevices, most probably and expanded/upgraded iPod Touch lineup, will be announced today….with at least some models paralleling the feature set of the high-end 2009 iPhone, including:

*One proposed marketing name for the new iDevices was “iPhone/iPod Touch X2,” denoting the “twice as fast, twice as much, twice the features” advancements over 2007/2008 models….

*Faster CPU (~600MHz ARM Cortex A8/similar, or perhaps a slight upgrade to the existing 412MHz ARM11 in the 500-600MHz range) competitive with the Palm Pre’s 620MHz Cortex A8 chip….and faster GPU (PowerVR multi-core, 5X+ performance gain over today’s iDevices) which supports Anti-Aliasing/Anisotropic Filtering, greatly improving visual quality at the same display resolution.

*256MB of DDR SDRAM main memory; twice the size, twice the bandwidth. This alone should not only greatly improve overall performance, it should bolster the stability of large games/applications and allow for even more ambitious apps to be developed.

*Dual-Band (2.4 & 5GHz frequencies) 802.11n Wi-Fi, which is 5-6X faster (300Mbps vs. 54Mbps) and offers superior range over existing 802.11g iDevices, as well as greatly reduced interference and more available channels in the 5GHz band. This will almost certainly bring along with it the capability to Sync wirelessly(!).

*Bluetooth 3.0, which can utilize the 802.11 radio for superior (8X faster, roughly 24Mbps vs. 3Mbps) bandwidth and range, and also fall back to the traditional Bluetooth radio for greater battery life when the additional bandwidth is not required. This will tremendously expand the possibilities for the use of Bluetooth with iDevices and the range of possible accessories in combination with iPhone OS 3.0.

*Built-in ~3.2 Megapixel camera with photo and video capabilities

*GPS and Magnetometer (Digital Compass) allow the iPod Touch to orient itself accurately in terms of both location and the direction the device is “facing,” supporting superior Maps & Directions functionality as well as a dynamic Street View based on the magnetometer data.

Many similar features are anticipated from a third, new iDevice family — widely expected to be something similar to the long-rumored ‘iTablet.’ With a large (8-10 inches plus) touchscreen display, lots of NAND Flash memory storage, and CPU/GPU even faster than those of other 2009 iDevices, the iTablet is one of the biggest outstanding questions of the day.

One thing we do know is that this new iDevice will bridge the iPhone/iPod divide by being available in both 3.5G wireless and non-cellular-enabled versions, allowing consumers to choose between go-everywhere cellular data connectivity and a less costly alternative with no monthly fees attached which would be limited to Wi-Fi and Bluetooth.

Many rumor-mongers are skeptical about an announcement today, predicting instead that it will be unveiled at a separate Apple Event which has long been slated for later this month. Either way, Rumors doesn’t anticipate that such an iTablet — whatever its final name — will ship until later this summer; possibly as far off as August or early September. This is the area of greatest uncertainty and we’ll just have to see how today’s Keynote plays out before speculating further.

Apple’s own recently revised internal roadmaps only specify “June” for an announcement date of this new iDevice, and “Summer” for a release. But given the x-factor of Steve Jobs’ return to full-time work at Infinite Loop and many other fast-moving, highly dynamic influences on Cupertino’s entire roadmap — the economy and the fortunes of its component suppliers being just one of many — a lot can change in the few weeks’ time since we last had the opportunity to look over those roadmaps.

Even more of a wild card is Steve Jobs’ rumored presence at WWDC — whether he takes the stage for part, all, or none of the Keynote, his mere presence suggests that expectations from even a few weeks ago could be massively out of date and wide of the mark even if they were entirely accurate at the time.

Will we see an entirely unexpected “One More Thing” surprise from Steve? It’s always a possibility….but one that even the most well-connected rumor-mongers can’t entirely anticipate. Stay tuned to Mac OS Rumors here on the Web and also on our Twitter feed for LIVE Coverage of the Keynote and ongoing reporting from the Moscone Center in San Francisco, our team in Cupertino, and contributors all over the globe who will be digging deep under the surface of this week’s announcements for the hottest dirt you won’t find anywhere else!