After the Windows Phone 7 launch passed without so much as a mention of Project Pink, Microsoft's other new phone project started to fade into memory. Today, we can confirm: Pink's coming, and Verizon's the carrier. UPDATE: First live shots.

A tipster passed us a load of 3rd-party marketing materials, in which a promotional plan for Pink is laid out in detail. (Campaign specifics and most graphics have to be witheld to protect the innocent, but rest assured, they're legit.) The documents don't talk about specs or software details, or more importantly why the hell Microsoft thinks this weird little pebble is a good idea, but there's plenty we can learn:

• The early Pink renders leaked to us back in September? Those are exactly the same ones included in the proposal.

• Of the two phones in prior leaks, only one shows up here: The Turtle vertical slider. It's a messaging phone, basically—one part Pre, and two parts Sidekick. (Or maybe three.)

• Verizon is a launch partner for the device, and probably an exclusive carrier. The branding and marketing in the documents suggests a joint Microsoft/Verizon launch, but another carrier isn't completely out of the question.

• The phones aren't running Windows Phone 7, unless it's hidden behind a different interface. Virtually all rumors around the Pink platform implied as much, and again, this appears to be something fundamentally different.

• Social Networking! It's all over the proposal, and presumably, the phone.

• It's suggested that the platform has apps of some sort. For a phone like this to share apps with Windows Phone 7 is pretty much impossible—the minimum hardware requirement for a Windows Phone look out of reach for this little black lump—so this one's a big question mark. Is it another SDK? Or closed app development like we've seen on the Zune HD? Web apps?

Since the documents come from a party working with Microsoft, and not Microsoft itself, a few things are missing: there's no mention of a release name for the product (Pink is the codename we've been using, but the launch title could be different.); stil no sense at all as to how the interface works; and no announcement or launch date. The documents are just days old, and hint at a near-term launch, which would be inline with what we've been hearing about a second Microsoft phone launch at or around CTIA at the end of this month. And remember, this are marketing materials, designed to promote a launch, not just an announcement. In other words, Pink, or whatever the hell it is, will likely beat Windows Phone 7 to market. So that explains all those Tweets, I guess.

All these missing pieces add up to a massive gap, not just in the phone's feature sheet, but in our understanding of what it's supposed to be. If it's a replacement for the Sidekick, the obvious question is, is anyone asking for a replacement for the Sidekick? If it's just a Microsoft-branded feature phone, er, why? Doesn't the future of youth/budget phones all about scaled-back smartphones (see: Pixi, Backflip), and not glorified feature phones?

UPDATE: More insiders have come forward, and now we have a possible timeframe: Late April. Oh, and there are two phones, as implied by the original leak. The second, according to our tipster, is the Pure horizontal slider, pictured below:

So these two phones - the Sharp PB10ZU and the PB20ZU - there are names for them but I can't tell you what they are, cause Verizon may just put out different code names in order to find out where any leaks occur. And frankly the names are really really awful sounding so I hope what I've been told aren't the final names anyway...

Apparently the interface shares some aesthetic elements with Windows Phone 7, albeit with "some sort of UI skin/more of a social-networking edge to [it]." As for release, apparently Verizon is "looking at a late April launch date," though this isn't set in stone. [Thanks, Tipsters!]