The Starcraft II Official Site shows the Terran and Protoss crests on the top-right side by the navigation bar. A fan noticed this and reported to have seen these same images in a Samwise artwork over at SonsoftheStorm.com.
Karune: These are not the official logos for each faction. Like almost all things in StarCraft II, they are still in the process of escalating the quality of the logos ”
RTS Community Manager | Blizzard Entertainment
These icons could probably be temporary placeholders and not final as hinted by Karune. Truth be told, once the Zerg Units are announced, it won’t surprise me closed beta won’t be too far. Keep your eyes on the Starcraft2.com website.
Source: Battle.net Forums