Reports are coming in  that “Google bombing”  doesn’t really work any more. Specifically, the theory is that now at least one of the words in the hyperlink text has to appear on the page being linked to, for the Google bomb to still be effective. But if that’s the case, why is George W. Bush’s bio page on whitehouse.gov still #1 for “miserable failure” in Google? I scoured his page for the word “miserable” and the word “failure” and found neither one! 😉 Look here  and you’ll see that Google couldn’t find the words either.
In any event, do bear in mind that focusing all your search optimization efforts on offpage factors and neglecting the onpage factors as well won’t bode well for your Google positions, I’m sure of that. And if you’ve hired an SEO firm that’s overly focused on the linkbuilding and not giving any attention to fixing your website’s search engine unfriendliness, you should probably reevaluate your decision.