The web browser aficionados at Opera have just launched an invite only beta program for the new version of Opera Mini. Opera has been promising for a year now that they were working on a version of Opera Mini for Windows Phone, and it looks like the app is almost ready.
Alas, it's a little too late to get in on the beta test.
Opera's web browsers for Android, iOS, Windows, and OSX are used by over 300 million people worldwide, so it should probably come as no surprise that the beta program is over-subscribed. According to the Opera website, they already have enough testers that they stopped accepting new ones and instead invite you to join the mailing list for notice of the public launch.
I, for one, don't have a Windows Phone, but I am on the list as well.