I think it's nearly as important to learn the "why" as the "what." It's cool to be working out scales and patterns, but I hope that you have a decent grasp of the chromatic chords up and down the neck. The scales take on new meaning when you can see how they intertwine with the chords. You don't need to be a master of music theory to learn scales, but if you have laid some of the groundwork w/ chords and neck positions the scales themselves will mean that much more.

Vibrato's something that just takes practice. There's a couple of different techniques, but I think a big key is timing and having a uniform vibrato. When learning, don't be as concerned with a huge variation from the base tone, but instead have the up and down motion be consistent, both in size (amplitude) and in timing (frequency). As you begin to master the technique, you'll learn how to control the amount you vary from the note.

I need to spend more time on the technical side of playing. I spend most of my time learning the ins and outs of all our Sunday morning stuff, and neglect a lot of the fundamental scales and such. It's a shame, because that can be a critical point for songwriting and arranging. Eventually my focus will change, but w/ my "real job," family, and worship leader responsibilities it can be tough to add "guitar hero" to the table.

Two I'd throw out there in the discussion would be:

Larry Carlton - "Kid Charlemagne" (actually, could also throw his work on "Don't Take Me Alive," same album)
Steve Lukather - "Hold The Line"

I tend to agree w/ Mark's assessment about being a good guitar solo...everyone wants to discuss the most technically proficient guitar player, but if a solo doesn't contain some redeeming musical qualities, it's just a bunch of strung notes. There is a difference between artistic creativity and regurgitating scales or simple muscle memory.