yep, anything fermented will have some CO2 in solution. several bottle priming calculators will take this into account (where it asks the temperature of your finished beer at bottling time, to estimate how many CO2 volumes are present)
its not enough CO2 to really notice on the tongue, usually, so it'll taste flat.
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10