easy way to disable filtering for specific tag in the excerpt

[hatul]

I think there should be an easy way to prevent the filtering of specific tags (such as a image or a paragraph) in the excerpt.
Now to add a specific tag I need to rewrite the excerpt function. For example:
​http://aaronrussell.co.uk/legacy/improving-wordpress-the_excerpt/

Should be action that marks the tags that not will filter.

[ocean90]

#12084