During the WAR preview weekend, I also tried the High Elf Swordmaster. I only took this character up to Rank 6. Again, I primarily did RvR Scenarios and Open World. The Swordmaster has a tiered mechanic. Your tier skills open up the second tier, and the second tier opens up the third. Everything below only applies to Rank 6 and below.
I am a shield kinda guy, so I went with that and a 1h sword. Your first skill is Graceful Strike. it is a nice damage attack, that applies a DoT and generates hate (threat). It will also put you into Improved Stance.
The Swordmaster is a tank class, so it does get a throw attack. I like the fact it can be much more powerful if you his someone with it from behind. That's what you get for trying to run away!
When you are in improved stance, you get Quick Incision. This is a damage skill and applies a slow on the target. Another nice Improved Stance skill is Eagle's Flight. It does damage, and increase your chance to parry. Avoidance is usually a nice thing to have when fighting multiple Black Orcs.
Nature's Blade is an interesting buff you can apply to yourself. You get a chance to steal a certain amount of points from a random stat on your enemy, for a short duration. So you could steal the Strength from the big Chosen you are fighting and use it against him. I wish there was more feedback on when this happens and what you steal. I really had no idea if it was working.
I only had one Perfect Stance attack at this point, Blurring Shock. It is a higher damage attack and resets you back to normal stance.
Overall, I really did not enjoy my time as a Swordmaster much. This is not due to the class itself as it is interesting and powerful. I just had a lot of trouble with the stance dance mechanic. I am a keyboard user for skills. I really had a tough time keeping track of what Stance I was in and what skill to hit. It got to be a bit aggravating.
With more time and practice, I am sure I would improve. However there are so many interesting classes, Swordmaster will probably be one of the last I roll when the game launches.