Having played the 'soul' series since Blade on the PS1, and being one of the tragically few people to have owned a Dreamcast with Soul Calibur 1, I was a bit dissapointed with the xbox incarnation of the series. I didnt find much evolution in SC 2, and number 3 was, frankly, poor.
I held out hope that this new gen of console would breath life into the franchise and thank goodness I have not been let down. SC has always had beautiful backgrounds and cut scenes, but in SC4 the character detail is on another level- the animation and graphical clarity during fights has never been better, with a real sense of solidity and depth to the characters. The 'create a fighter' mode is great, even if you cannot combine move sets from different characters. The inclusion of the Star Wars universe does not grate on me as much as I though it would, and Yoda leaping about like when he fought Duku in the movies is a lot of fun- at least he is a bit 'different' and not like Spawn in SC2, who felt merely like a familiar fighter with a different character model patched over the top.
The joy of the SC series is that, for purists, there is depth, but it still allows 'button mashers' to pull off some great combos. Some see this as a fault, but i love the fact that in vs mode I cant take for granted that I can beat someone less familiar with the game- every fight is challenging.
I am not online, but can only presume that, providing there are no lag issues, the vs mode will be as entertaining as it is in 'meatspace'.
If you loved SC, but felt let down by number 3, then let this game restore you faith in a truly great gaming series- its the best its been since it lived on the Dreamcast.