Yes, but not all games designed for 49-way joysticks. A lot of them MAME has hacked to 8-way control, so even if you use an analog or a 49-way, you will only get up, down, right, left, and the diagonals.
Unless things have changed recently (and I'm kind of behind the times on the software, so somebody correct me if I'm out of date), Sinistar and Blaster are the only ones official MAME has setup for analog control.
Arch Rivals and Pigskin 621AD are supported through MAME Analog+ for 49-way, but I don't know about analog.
Last time I checked, the rest of the 49-way games were either not working, or hacked to 8-way control.
Your analog stick will also play the Hall-Effect joystick games, like Roadrunner.