There is some native support in Galaxy S2 for exchange calendar. In GS2, you can receive the Calendar updates by possibly setting up your email account and enabling exchange sync for calendar. No extra application or configuration required.
Once you setup the email account, open the email, go to account settings and you should see an option to sync calendar.
Using google calendar,
You are able to view your calendar from outlook 2007, but not able to create new entries. I use thunderbird as email client and same setting works fine for reading and editing.
Google sync. You have to install this application in your PC and it syncs your exchange calendar with google calendar.
I tried this and it works for me. I saw some forum comments where people complained that the software was not stable.