What steps will reproduce the problem?
1. Using Selenium Server 2.0b3 (Selenium component, not webdriver), navigate to www.google.com
2. Attempt to click on a link using the locator "css=a:contains('^About Google$')"

What is the expected output? What do you see instead?
Expect: Click on the link "About Google"
Actual: console reports "ERROR: Element css=a:contains('^About Google$') not found"

What version of the product are you using? On what operating system?

selenium-server-standalone-2.0b3 on Windows 7 64-bit.
This issue does not repro (i.e. it works as expected) with selenium-server-1.0.3 on
the same hardware.

Please provide any additional information below.

This is not a widely documented feature of Selenium but I use it quite extensively.
I found out about it via the Sauce Labs blog. See the "Matching by inner text section"
here:
http://saucelabs.com/blog/index.php/2010/01/selenium-totw-css-selectors-in-selenium-demystified/
I use ruby (selenium-client), some simplified code to repro:

page.open('http://www.google.com')
page.click("css=a:contains('^About Google$')")

Note: if you remove the anchors ^ and $ from the locator the code will work, but this
allows for loose rather than exact matching.