Yep, 6.5" and they are eager to be replaced if you're so inclined. MB Quart, Infinity, and others make some great 6.5" speakers that project the high-tones much better than the muffled cone speakers that currently reside in the snake. If you like a "crisp" sound I recommend the MB Quarts and if you want bang-for-the-buck you might look into Boston Acoustics.
Another bonus is that the speakers are connected to the amplifier, making a simple swap all that much easier. In other words, you don't have to worry about adding more driving power to the speakers unless you add non-powered subs.