Given Facebook's cavalier attitude towards its users' personal data, it simply has to be Google.
A Facebook deal would invariably see Twitter profiles being linked to their owners' Facebook pages, probably without consent, forcing more tedious opt-outs.
It would give Facebook more control and more leverage over its users personal lives, and this is not to be welcomed.
In fact, we foresee uproar in the Twittersphere should any deal swing in Zuckerberg's favour.
Now, we're not wild about Google getting its foot in the door either, but in this case it is very much the lesser of two evils.
Connection is good, but diversity of choice should always win through.