Given your definitions of 'rationalism' and 'empiricism,' an empiricist would need to assert that informative priors, if they exist, either are not "novel information about the world" or are novel information that we derive from experience. We aren't perfect Bayesian reasoners, and you haven't defined 'information,' so this doesn't seem perfectly open-and-cut to me.
One approach an empiricist could take would be to deny that our primordial priors (i.e., our earliest expectations), in themselves, constitute information about the world; perhaps we can use them as a handy framework for genuinely informative research, but the framework itself is not knowledge,
Another approach would be to deny that we have expectations before possessing any sense-perception; perhaps neurological development relies extensively upon sensory input from our environments before anything as cognitively complex as 'expectation' or 'belief' enters the picture.
Or one could adopt a mixed strategy.
Despite being (IMO) a philosophy blog, many Less Wrongers tend to disparage mainstream philosophy and emphasize the divergence between our beliefs and theirs. But, how different are we really? My intention with this post is to quantify this difference.
The questions I will post as comments to this article are from the 2009 PhilPapers Survey. If you answer "other" on any of the questions, then please reply to that comment in order to elaborate your answer. Later, I'll post another article comparing the answers I obtain from Less Wrongers with those given by the professional philosophers. This should give us some indication about the differences in belief between Less Wrong and mainstream philosophy.
Glossary
analytic-synthetic distinction, A-theory and B-theory, atheism, compatibilism, consequentialism, contextualism, correspondence theory of truth, deontology, egalitarianism, empiricism, Humeanism, libertarianism, mental content externalism, moral realism, moral motivation internalism and externalism, naturalism, nominalism, Newcomb's problem, physicalism, Platonism, rationalism, relativism, scientific realism, trolley problem, theism, virtue ethics
Note
Thanks pragmatist, for attaching short (mostly accurate) descriptions of the philosophical positions under the poll comments.
Post Script
The polls stopped rendering correctly after the migration to LW 2.0, but the raw data can be found in this repo.