MacBook Pro Battery bulging/swelling - your experience?

Hi Guys,

some weeks ago i noticed the trackpad on my MacBook Pro (Late 2009 13'') became unclickable. Checking the unibody i noticed some deformations. When i tried to remove the screws the lower body nearly jumped at me and it felt like the battery "exploded". See attached photo.

I was wondering what your experiences are regarding swelling/bulging batteries if the product itself is out of regular warranty? Any reports of successful fairnesss replacements?

Thanks: L