Hey guys, found this glitch while messing around with specs. In order to do this, you must have dual-spec. One of the specs needs to have the Improved Frost Presence (IFP) talent, and one has to be without. Switch to the spec with IFP. Switch to Frost Presence, then switch to Blood or Unholy Presence. Since you have the talent, your health should remain the same. Now, while still Blood or Unholy, switch specs to the spec without IFP. You should have the extra 10% health you got from IFP, without having the talent.
Be in Frost Presence, with the Improved Frost Presence talent.
Switch to Blood or Unholy Presence.
Switch specs to the one without the Improved Frost Presence talent. You should keep the 10% extra bonus.
*Note: Switching presences after doing this exploit will remove the extra 10% health from Blood and Unholy Presences.