I thought InnoDB had a count, too. Don't worry, I'm happy with Wikipedia
servers not crashing. :)
Do doing things the slow way:
mysql> SELECT COUNT(*) FROM revision;
+-----------+
| COUNT(*) |
+-----------+
| 416988781 |
+-----------+
1 row in set (1 hour 36 min 52.58 sec)
Result from about 1.5h ago. Probably the count from when it started.