It's planned for a future update, not now. Currently, titles are only stored per character, but that will change in some fashion when they update the HoM.
I'm assuming you mean HoM (Hall of Monuments), not HoH (Hall of Heroes)
What they're going to do (or maybe did with the Dragon Festival, I honestly haven't checked) is give you the option to make your Hall account based. This means that if you've got a mesmer who's Legendary Spearmarshal and a necro who's Legendary Survivor, you can put both statues in the hall. That does not mean all titles are account based (your mesmer couldn't claim Legendary Survivor unless he did it himself), and I believe it doesn't mean you can put up an infinite number of statues - I assume it's still your five biggest achievements.