Hi
Thats true.
For a full redundant network you need both L2 Redundancy that can be achieved be a nice plan of MSTP.
And also you need L3 redudancy which i believe Matt already spoke about it.
One more thing i would like to add, XRRP is an HP proprietary protocol while VRRP is an IEEE standard one.
Each one has its own advantages and disadvantages, and from my experience, XRRP is faster recovery than the VRRP.
But in a complicated environment i would go for the VRRP for more scalability in the Network.
Good Luck !!!