If one were to read Hugh Muir's politics diary at the Guardian UK, one might get the impression that Condoleezza Rice were slyly passing judgment on Sarah Palin or hints to herself by manipulating the Great Seal (cf. Barack Obama's glossy Seal 2.0, whose Latin phrase sounds whiny to me: "Really, we can!"):

Is Condoleezza Rice, who was often spoken of as a potential Republican presidential candidate, fully on board with the Sarah Palin phenomenon? She seems to be dropping hints that she might be still available, for now, or perhaps when the cavalcade rolls again in four years? On her recent trip to Libya on Air Force Two, the napkins that came with the drinks bore the great seal of the US; except that instead of E pluribus unum "From many, one", the legend read E pluribus unam. Most took this to be a misprint, but Latin scholars noted that unam is a feminine form. From many, one woman, is it? Which one?

It is a typo, and it says nothing about Condoleezza Rice that someone made a mistake on a cocktail napkin.

How do I know it's a typo?

Because I, unlike those mentioned by Muir, actually am a Latin scholar.

In the phrase e pluribus unum, the word unum (neuter gender) is in the nominative case, the case that names the subject. But unam (feminine gender) can only be accusative, the case that marks the object of a transitive verb (among a few other things, e.g., extent of space or duration of time).

The formulation with unam is meaningless without a transitive verb, while unum is a purely descriptive phrase not requiring a verb of any kind.

As an aside, e pluribus unum makes better sense when considered not as "one out of many", which is ambiguous, but rather as "a union (composed) of a great many (states)". (The preposition e/ex with the ablative case--i.e., e pluribus--can denote the material out of which a thing is composed.) That's why it's part of the Great Seal of the United States: it speaks specifically to the nature of the union, not about a melting pot, not about pluralities, but about many states forming 'one thing' (unum).

In fact, I wouldn't be surprised if the neuter idea underlying unum were not foedus, a kind of "covenant" or agreement underlying the idea of federalism. Then we're talking about one federal government which depends upon a great number of constituent states, and the very essence of the nation depends upon maintaining the sovereignty of those constituents.