There are definately stereo speakers on the front, one at the top and one at the bottom under the grills. There is also a third speaker on the back, yes three in all!!
I have done extensive sound listening tests to confirm this and it is most noticable if you turn Dolby Mobile on in the Sound Enhancer section which gives a better stereo separation effect. You really have to play music on the handset to hear all three speakers.
The front stereo speakers are not listed in any of the spec I have seen but this is a complete bonus as far as I am concerned. It will even be a huge benefit for sat nav applications guidance voice when they become available.