The Toast UI metaphor is useful for showing transient messages to the user such as authentication failures or other other messages that do not require the user's immediate attention.

In the current ShellTile API, a toast will not be displayed if the current foreground application is the caller of the ShellToast.Show method. It would be great if this was changed so that we could present in-app toasts. We can then user the NavigateUri property to navigate the user to a different part of the app if necessary.

All types of files should be allowed to be shared via Bluetooth between WP and any other devices..

Add Ability to set referrer and other custom headers when using HttpWebRequest

Please show the scrollbars in the WebBrowser control. For details and a workaround that's not working as smooth as it is when it was implemented in the control itself.

http://www.pitorque.de/MisterGoodcat/post/Somethings-Missing-from-the-WebBrowser-Control.aspx

It would be really cool if developers could get api access to Xbox Live Gamertags, that way they don't have to make users create a new account just to play multiplayer games. It would also help a lot for leaderboards too.

For those of us wanting to provide free applications it would be nice if the WP7 supported self signed certs or the very least a widely known free SSL authority.

Add ServicePointManager.

Or at the very least add a free service to your accepted list of SSL authorities. Like cacert.org for instance.

Currently, I can detect and control what the embedded Zune player is currently playing.
The same can't be done with 3rd party apps implementing background audio streaming like soundtracker etc.

We are limited of saving the Images to the Media Library.
It will be better if user can add the downloaded Audio , Video can add to the Media Library from the Isolated Storage.

Support for Wifi-Direct enables a lot of user experiences like fast device to device communication. It is supported on Windows 8 and I really hope this will be added soon to Windows Phone.

Many universities use 802.1x authorizations for their wifi networks. On WM6.5 a program called SecureW2 was used however there is no such program for Windows Phone 7. On and Android and other iOS devices there are methods to connect to 802.1x networks. Will there be any new implementation of this in any new updates for windows phone?

Single task is back
Please support a task running in the background, or snap. And you can switch, similar to Win8.

Allow video to be treated as an object, such as Texture2D, so that it can be sized, positioned and incorporated into gameplay.

I think WP7 contains a superior user interface to other mobiles OS's.
However the screen lock code seems out-of-date and sub-par to the rest of the interface. Android allows you to setup a graphical pattern, for example, while WP7 only allows you to enter a PIN code.
A graphical pattern is more practical and user friendly that a PIN code.
I don't think this is a difficult thing to implement and would improve the user experience.

The current auto sync with skydrive compresses pictures before uploading. This way still no real backup is made. Since skydrive offers 25gigs more then enough space is available for backing up in full size. Create an option to 'only upload to skydrive when connected by WiFi' and an option to choose to compress or not.

Mango provides a good feature to scan an image for a text. It would be great to provide a new launcher/task which uses this new existing funtionality to get a string from an image.
Otherwise we need to create our own control to scan an image and extract strings with an ocr library. I'm not happy to implement something which is already there.

Even if this API would use a webservice and needs network access, I would be fine with that.

Needed to create pro level sequencers, synths and music creation related apps!

Flash Player should be there so that more flash games and videos could be played.