This is an old preview/trailer of Rockman X4 from an equally old April 1997 Multiple Option CFC (Capcom Friendly Club) Style videotape from Japan.
[youtube]http://www.youtube.com/watch?v=38HMT8z39Ak&feature=player_embedded[/youtube]
While this preview may not include much immediate beta/pre-release differences, there is one particularly noticeable element that can be heard in this video. For one, X sounds completely different as you see him jump and shooting out charged buster shots in the video; we're talking about a pre-release video of the Japanese version here. Apparently, he had a different voice actor, as he sounds like a girl, much like he does in the English final version of RMX4. Zero also sounds slightly different as well, his Saber slashes are odd too.
---About this April 1997 Multiple Option CFC (Capcom Friendly Club) Style videotape---
Now, in this very same videotape, theres also interviews of Keiji Inafune, Shinji Mikami, Yoshiki Okamoto, Akira Yasuda, and the Rockman Battle & Chase music team.
There's also video footage from other Capcom games in pre-release/trailer form including (not in any order):
+Press Start 2 (Actual Title?)
+Street Fighter Collection
+BioHazard/Resident Evil 2 (1.5 prototype version)
+BioHazard/Resident Evil 1 (Sega Saturn version)
+Some Trivia Game (Quiz Dreams, etc.)
+Dungeons & Dragons Collection
+Super Adventure Rockman (This didn't come out until Summer 1998!)
+Rockman Battle & Chase
+Breath of Fire III
+Marvel Super Heroes
+Marvel Super Heroes vs. Street Fighter
+Vampire Savior: The Lord of Vampire
+Battle Circuit
If you want, I can rip the entire tape to show everything. Just ask! Demand!