I've been working on a new mining frontend called SlushMiner, it's similar to GUIMiner but with some improvements:

• At the moment it's designed to work specifically with Slush's Pool. You log in using your API key and your list of workers is pulled down, along with your account statistics. (I recently added the ability to override the worker information in case the Slush's Pool API goes down like it did recently)
• Exchange rates are pulled from Bitcoincharts.com, allowing you to see your reward balances in whatever currency you like.
• Support for proxy servers, along with better exposure for options like vectors, frames, and sleep.
• Detailed tooltips for every feature in the program.
• Charts for statistics like hashrate and accepted shares per minute

.NET Framework 3.5 SP1 is required, along with Windows XP or newer. Both 32-bit and 64-bit systems are supported, and this program uses a Stratum-compatible POCLBM backend. This program is geared especially toward new Bitcoin miners, but it exposes a number of settings for experienced users as well. At the moment the program only works with Slush's Pool, the POCLBM miner, and currency info from Bitcoincharts.com, but in the future I plan on working on an addon-type system to allow other pools, other miners, and other currency market sources. (At that point I'll likely rename it to something more generic)

I've been posting this program in the newbie forum since I just recently created my account, but since I got whitelisted I'm creating a topic here too. I'm up to version 0.2 at the moment, and it's still in alpha stages so there's bound to be bugs in it, but if anyone would like to try it out and let me know what you think I'd really appreciate it! I'll be releasing the C# source code soon, I'm almost done cleaning it up.

Download SlushMiner: https://sourceforge.net/projects/slushminer