From heartbleed.com:

The Heartbleed Bug is a serious vulnerability in the popular OpenSSL cryptographic software library…
allows anyone on the Internet to read the memory of the systems…
compromises the secret keys…
Exploitation of this bug leaves no traces…

In short, any service you’re using that has an “https://” connection might not be as secure as you think it is.
Even Wikipedia’s article on Public Key Cryptography agrees that:

Loss of secrecy and/or authenticity, even for a single user, has system-wide security implications, and a strategy for recovery must thus be established.

As of writing these lines, this service allows you to check whether some site is compromised or not. The following is a screenshot for its output for statstrade.com: