1. StarDust beat MC 2-0 at IEM Cologne. The games lasted 6:56 and 8:38 with MC attacking early in both games (ref)
2. MC is 3-9 (25%) in PvPs lasting 20-25 minutes, but 6-1 (86%) in PvP >25 minutes (ref)
3. MC is diligent in using his Phoenixes. Although he makes slightly fewer (.54 v .65) Phoenixes per game than his opponents, he uses Graviton Beam more often (2.81 v. 1.61) (ref 1) (ref 2)
VortiX (Z) v. jjakji (T)
1. VortiX opened Hatch First in 18/20 (90%) of ZvTs. It's usually a 15 Hatch followed by a 16 Extractor or Pool. (ref)
2. VortiX is 4-0 in games 8-12 minutes long, all of which were Roach Baneling all-ins. However, he's only 4-4 in games going Roach Baneling overall (ref)
Alicia (P) v. Bomber (T)
1. Alicia is 19-6 (76%) in games longer than 16 minutes, while only 69% overall. (ref)
2. Don't play Bomber straight up in TvP. He's 2-7 in games <16 minutes and 11-4 in games >16 minutes. Blink Stalkers and Dark Templar are good bets (ref 1) (ref 2)
TaeJa (T) v. HyuN (Z)
1. At ASUS ROG Summer 2013, TaeJa beat HyuN 3-2 (ref)
2. HyuN can be deadly in the early game. He's 9-0 before 12 minutes and 13-2 before 16 minutes (ref)
I used the data from Spawning Tool to generate all of these statistics. Notably, replays for WCS 2013 season 3 and the current WCS season have not been released, so those are not included in the current sample. Some players have more data from other recent tournaments, whereas others may be based on older data with different play styles.
If you get chance, please poke around with the data on Spawning Tool and share any other interesting trends you find!