There are a lot of websites that discuss the poor mouse performance in VMware on a Microsoft 2008 R2 server.
One of them is the wrong VGA driver in your 2008 R2 server. There is a good solution to be found over here: http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1011709
Another one is the mouse driver. Follow the instruction below.
Log in on your Windows 2008 R2 server.
Go to your device manager: Control Panel > view by small icons > Device Manager
Open 'Mice and other pointing devices' shown below. When you check this, you see the reverted "PS/2 Compatible Mouse" driver.
Change it to 'VMware Pointing Device' and I would bet that resolves the problem. Driver is located at C:\Program Files\VMware\VMware Tools\Drivers\mouse. Right click and update your driver shown below. Choose Let me pick from a list of device drivers on my computer and click Next.
Choose 'VMware Pointing Device' and click Next
As you can see after the reboot you can freely move the mouse without any delay
You are ready to go. Enjoy your Microsoft 2008 R2 environment