That's awesome news. Congratulations to the Wufoo team -- it is well deserved. (Their product is awesome.)
It is also great news for SaaS startup generally, since Wufoo is a little of column A and a little of column B on the typical grow via revenues VS get investment and grow massively dichotomy. That's a data point in the favor of at least some investors making investments in companies which have a projected trajectory where massive success results in a company on the scale of 37Signals/FogCreek/Wufoo rather than resulting in a company on the scale of Zynga/Groupon. $35 million won't exactly have VCs salivating but, oh well, if they don't invest they don't get a vote -- the angels and employees of Wufoo have to be happy like clams at this outcome.