1: Install SIMBL (plugin enabler):
2: Install the TerminalTabSwitching.bundle
git clone https://github.com/dabeeeenster/terminaltabswitchingcp -r terminaltabswitching/TerminalTabSwitching.bundle "/Library/Application Support/SIMBL/Plugins"
3: Restart the Terminal app, and enjoy Cmd+[0-9]
tab-switching.