AirDrop requires a computer newer than your MacBook Pro: http://support.apple.com/kb/HT4783
As I understand it the wireless hardware is the limiting factor.
Macs that support AirDrop in OS X Lion
If your Mac is the same as, or newer than, the models listed below, then it supports AirDrop.
- MacBook Pro (Late 2008 or newer)*
- MacBook Air (Late 2010 or newer)
- MacBook (Late 2008 or newer)*
- iMac (Early 2009 or newer)
- Mac Mini (Mid 2010 or newer)
- Mac Pro (Early 2009 with AirPort Extreme card, or Mid 2010)
* The MacBook Pro (17-Inch Late 2008) and the white MacBook (Late 2008) do not support AirDrop.
Actually Airdrop is supported on Older macs, but is not visible; if you want it to be visible follow my steps:
1. Open Terminal
2. Insert the following command:
defaults write com.apple.NetworkBrowser BrowseAllInterfaces 1
3. Once complete insert the next following code: killall Finder
4. This should have fixed the issue, to test this goto Desktop>Menubar>Finder>Go>Airdrop
I hope this helped