It’s rumour time again, with a number of rumours we’ve heard before suddenly surfacing again, this time with renewed plausibility (or not, depending on your level of cynicism!)

First up is Microsoft, who are apparently working on their own smartphone according to analysts at Broadpoint AmTech. The aim of the smartphone is to act as a showcase for the forthcoming Windows Mobile 7 and to “…tightly integrate hardware and software”, like Apple’s iPhone or RIM’s BlackBerry.

Broadpoint AmTech speculated that a Microsoft phone would be based on the NVIDIA Tegra chipset that HTC will soon be using, and so will be capable of supporting 3D and HD video.

More likely, with the current smartphone market threatening to crowd out Windows Mobile (Android, the Palm Pre, the iPhone, Symbian, and Blackberry all offer better alternatives to the shoddy design of Windows Mobile 6.x), Microsoft know that soon no-one else will be building a Windows Mobile phone, so they’d better do it themselves to keep the OS alive!

More news on Dell and Twitter after the jump.

A Dell smartphone in the works?

Dell have been rumoured to be working on a smartphone for a couple of years now, but despite pinching ex-Motorola Mobile Devices President, Rob Garriques, nothing came of the rumour.

Actually, maybe it was because they pinched Garriques that nothing happened, as it was on his watch as mobile device VP that Motorola went from mobile colossus to the money-haemorraging mess it is now!

With the recent explosive growth in Netbooks threatening to eat into the traditional home PC space, Dell need to do something to break into this market. Developing a smartphone, therefore, is a smart move, as smartphones and netbooks are converging, and there’s more money in phones than in Netbooks.

Current rumours suggest we’ll see a new Dell smartphone at MWC 2009 in two weeks’ time, but personally I think this is much too soon. Late 2009, would be my guess.

A Twitter phone?

Finally, the Tiwtter phone. Twitter themselves aren’t working on such a device, but then they don’t need to. Their API is used by seemingly anyone capable of throwing together a few lines of code, and so twitter clients have already appeared on virtually every type of mobile phone on the market.

No, what is new is that the INQ1, the so called Facebook phone from Three, is being modified so it’ll also be a Twitter phone. Electric Pig asked INQ CEO Frank Meehan whether the next version of the INQ phone (provisionally called the INQ2) would include Twitter in a similar way to how the INQ 1 supports Facebook, he said “I think we’d be stupid if we didn’t but we haven’t confirmed it yet – you want to do it properly.”

So there you go – three rumours in one day! My guess is that Dell will definitely produce a smartphone before the end of 2009; Microsoft will sit on the sidelines for a while, waiting to see how Windows Mobile 7 is received, then promptly develop their own mobile phone when they realize their technology is years behind everyone else’s and is both unwanted and unused – so they’ll develop their own phone sometime in 2010; and the Twitter phone will come out in the second half of 2009, but won’t feature anything substantially different from what you can do on Web-enabled phones such as the iPhone, Android phones or the new Nokia N97.

[Source: Pocket Lint, ElectricPig]