I did a search but saw results on this yet but Opera Mini 5.1 is available. I tried it and it very fast. Here's the download link:
http://m.opera.com/mini5wm.cab?act=dl&tag=mini5wm
NEW FEATURES- Ability to set Opera Mini as default browser on the device.
- Support for g-sensor screen rotation on HTC and Samsung devices.
- Support for predictive input if the device supports it natively.
- Improved page layout on high-resolution screens.
- Improved kinetic scrolling.
- Use HQVGA skin for devices with less than QVGA resolution.
- Installer is now signed with VeriSign so Opera Mini will be a trusted application on your handset.
- Alternative installer that works on Windows Mobile 2003 Pocket PC devices.
- Advanced configuration in registry for power-users (see here for more information).
BUG FIXES- Multitap input is working on 'classic' keypad devices.
- Input is working on qwerty keypad devices by Samsung and Amoi.
- Keypad shortcuts working on more devices.
- Ability to download files to memory card.
- Clock in Opera Mini is correct in all time zones now.
- Spanish locale is correctly detected.
- URLs and downloaded files can be passed to other applications as a platform request.
- Many bug fixes in Opera Mini browser core for stability and rendering accuracy.