This setup is fine but know that optical cables cannot output the new, uncompressed audio formats found on blu-ray, namely DTS-HD and Dolby TrueHD.
If your amp does not handle these uncompressed formats anyway, then you're fine. You can still receive dvd-quality sound (5.1, DTS, etc.) via that optical cable- just not the newer uncompressed stuff.
Ideally you should have an amp/receiver, blu-ray player and TV with HDMI version 1.3. Then you would hook up the blu-ray player via HDMI to the amp/receiver (instead of to the TV) so the amp/receiver can output DTS-HD and/or Dolby TrueHD. You would then use an HDMI cable from the amp/receiver output to the TV input to get the video signal out.
But if you're not experiencing lip sync issues / audio lag then you're fine as-is.