Even if you move out without a tenant in place the landlord has a duty to attempt to re-lease the property in a timely manner. You are liable for the difference to the landlord in that case.
You bought a home at a great (presumably) price in this market. If you spend some money in breaking your lease consider it a moving expense. If you saved $50K on your purchase yet spend $2K by breaking your lease you are still way ahead.
Talk to your landlord and work together to get a new tenat asap or mitigate your expense. If push comes to shove, honor your ethical and financial committment to your landlord and move forward.
Before simply "breaking" your lease, check with your attorney or a local housing or tenants rights group.
Congratulations on your new home and best of luck!
For example, if it's allowed by the landlord or property management, you may be able to find someone else take over your lease. Brush up on the California Landlord/Tenant Law where it says that "The disadvantage of a lease is that if you need to move, a lease may be difficult for you to break, especially if another tenant can't be found to take over your lease. If you move before the lease ends, the landlord may have a claim against you for the rent for the rest of the lease term."
Go to this site for mnore information http://www.dca.ca.gov/publications/landlordbook/index.shtml
Look at your rental agreement carefully, go to the landlord and ask if they will let you out of the lease and under what tems. A lease is a lease and purchasing a new home is not usually an easy out. Good luck.