In Mango I do not see a way to subscribe to a podcast by entering in the URL. There should be a way to do this. I am liking the new download over WiFi feature.

private/corporate WiFi authentication with a certificate is not supported at Mango.

To be able to make a movie (and share it with the rest of the World via youtube) we need an ability to generate MPEG4/WMV stream/file by utilizing hardware codecs (through FileSink). Also some way to change (enhance) audio/video captured from mic/camera before it will be encoded and saved into file.

native Midi file support

Please allow the access to Gmail's Todo list sync when a google account is added on the windows phone. Under calendar I see the todo list of hotmail and I like it, it would be great if I can add the gmail's ones too and have the ability to make changes when sync happens or just have the ability to add todo items and those get sync to the phone.

In addition to the existing database support, please add support for SQLite databases, without a LINQ layer like for SQLCE. Just a raw database with SQL commands like we are used to. SQLite is platform independent, that means it is easy to exchange data between Windows, Windows Phone, Android and iOS devices.

like Name of that caller
Phone Number
Etc.

With WP7 I could view pdf and office dos with the WebBrowserTask. With Mango this is not possible anymore when having one-time-generated urls.
The request is now being called twice! Please fix this... otherwise my (and some other) apps/functions are not usable anymore :-(

See: http://forums.create.msdn.com/forums/p/88705/548248.aspx

You are running an application that records your GPS position after traveling so many feet. If for some reason your application gets deactivated (you receive a phone call); your recorded track will be missing data for the time you were on the phone. This can be a serious problem if you need to follow the track back out. What this forces the user to do is carry a hand-held GPS as well as a phone when the track log is important.

Open up the OS enough for someone to write a professional level direct sync app for Outlook on the desktop.

more and more people telephone over voip but there are many different provider. they all use Sip so it would be great to have a native sip client integrated.

There is a feature in windows 8 for roaming application data which allows Windows 8 automatically transitions certain application data between user devices.
I suggest to have access to user's roaming data from WP8.
For example, user can play a windows version of a game as well as a mobile version of the game and scores will add up.
Follow up:
It looks like Microsoft is planning to do that but the functions are not implemented yet.

there must be an application to record the conversation on a call.

Currently, there is no way of knowing if a user converts from our own advertising campaign or "out of the blue". It would be great if we could link to an app's store page with a campaign code, and get the breakdown by campaign codes in our daily stats. For example:

United States Paid (after trial) 32
United States Paid (after trial, campaign XYZ) 64
United States Paid (without trial) 16
United States Paid (without trial, campaign XYZ) 48
United States Trial 192
United States Trial (campaign XYZ) 284

Put (blinking) LED notification when having incoming notification to save effort every time do not have to unlock screen and checking any notification. Nokia symbian phones does have, would like window phone will have too.

I want to create an application which creates an automated statistic of the time I spent to my phone calls.