The only personal information stored on the epassport chip is the same information you see printed on your passport data page - like your name, date of birth, etc. Additionally, there is other digital security information stored on the chip that proves the passport and its data are authentic. This includes one or more biometric identifier, which is used to verify that the person presenting the passport is really its owner. The biometric requirement can vary from country to country. There is also a digital version of your photograph.
Currently there is a plan to also add fingerprint biometrics, following a European Union directive.
Germany, for example, already has two fingerprints, one from each hand, in its passports. All European Union countries are working this feature, and are currently conducting cross-border tests of these more advanced epassports.