I guess this is a very hot topic now where Google just launched their latest Search Engine formula called Google Caffeine. Most of the webmaster will have concern on how will this impacted us? The answer is yes, it will impact us if your site has been established for more than one year.
All you need are as below:
1) Go to normal Google.com and perform the search, check your position
2) Now go to http://www2.sandbox.google.com/ and try to check the same search again, if the position is similar to what you have in step 1, then you are safe.
3) If your result in step 2 has a lot of differences, then your need to fine tune your site like description tag, keyword tags and title tag, upload and try it again.
So far, I have fine tune a few pages on my site and it looks good now. Hopefully this is something that I think is good to know for now so that you can perfrom some changes now.