I work at a small company (80 employees), when we deployed MS Exchange anyone who connected their iphones using the exchange connector lost the icon to the camera on the home screen. The engineers made some changes and the camera icon returned. What other access / control does the exchange team have over our phones? Can they view email (personal and exchange?), photos, web history etc?
From a quick glance at http://www.apple.com/iphone/business/integration/ -- Exchange can set password policies, network access (including VPN), restrictions on use of YouTube and iTunes, prohibit app installs and use of the camera.
More information at: http://manuals.info.apple.com/en_US/Enterprise_Deployment_Guide.pdf
I don't see anything about viewing web history, etc. -- but if you are on a company WiFi they could theoretically see what websites you are viewing.
They can reset your iPhone remotely. That's for certain. I had to go through that process when I left my old employer and had my personal iPhone connected to work via the Exchange Connector. You'll be able to restore it from a recent backup.