We were all pretty intrigued to see what Ballmer would reveal at Mobile World Congress. Ee knew it was going to be Windows Mobile 7, but would it be up to scratch?

Let's face it, we're annoyed at the long-winded Windows Phone 7 Series moniker (not least because it ruins our headlines), but we have to say there's more than a glimmer of hope about what was unveiled.

And now we know more - from the MIX 2010 event where Microsoft shone a few more lights into the murky mysterious of WP7S. It's not a lot to go on, but enough to get a much clearer grasp over Ballmer's vision.

1. Putting developers first

The sheer weight of information unveiled about developer tools at the MIX event (which, admittedly is based around developers) showed that the Windows Phone 7 platform is all set up for apps.

Ballmer

CREDIT: Engadget

Devs will be able to take advantage of elements like multi-touch, the camera, GPS, push notifications and accelerometers to make cool new applications.

Steve Ballmer was also parodied in a demo app using Silverlight - onlookers were given the chance to watch a bobble-headed version of the chief yelling 'developers, developers, developers' over and over again.

2. Marketplace overhaul

If you're making apps, you need a place to put them. To that end, Microsoft has decided to overhaul the Windows Phone Marketplace, so it now features a panoramic design and 'active merchandising' to increase the discoverability of games and applications.

It also supports one-time credit card purchases, mobile operator billing and advertising-funded applications to increase the raft of options on offer - basically offering more ways to pay makes developers happier.

3. Bye bye multi-tasking - for now

For Windows Phone 7 Series, the OS will process Microsoft's core integrated experiences, including music and phone calls, in the background, but NOT those of third-party apps – very much like the iPhone.

The new Microsoft phones (Microphones? Oh, wait...) will, however, support push-notifications so that third-party apps can send you updates and status messages when the app itself is not running in the background.

And don't worry if you're a huge WiPho fan - this isn't Microsoft's final stance on multi-tasking - it's just set this way so the first release doesn't go all unstable and eat your battery.

Windows phone

4. There's real power under the hood

Microsoft used the MIX event to show off what can be achieved with the new WP7S (unsurprisingly).

In the unveiling, it showed off an application from the Associated Press (that included in-app advertising) as well as pointing out the ability to jump to pictures and video.

Basically, it seems that the apps will be able to draw from the phone's resources in a big way and still survive - which makes sense when you think it's going to have a 1GHz processor as a minimum in most devices.

5. No more memory cards

Here's a down side - there won't be any memory card support. Actually, check that - there will be support for them, but you can't get to them.

That's right - the two options will either be inbuilt memory, and gallons of it, with no memory card slot (think Nokia X6) or there will be a 'locked' memory card under the battery.

Why? We have no idea. It seems that if you can support hot-swappable memory cards, you should. It just makes life easier for the end-user.