Ive been doing these excersises for about 5 months and my pinky isnt getting any stronger and i feel like its not really teaching me how to play. I still cant shred because i dont know how to use notes to improvise? ';[
My thoughts on the subject - http://www.youtube.com/watch?v=ZcEHxH4S9_c

Exercises are specific tools for specific problems, not a cure-all.

Also, seriously - learning the fretboard and training your ears is massively more important than learning to "shred".

Honestly, say you could attain Petrucci levels of speed - you can't even pick good notes at your current speed. How are you going to pick 15 good notes every second?
Exercises make you great at those Exercises, they might help with things all around but in the end you're training yourself to play fast which can only get you so far. As far as Shred, make sure you are fabulous on Rhythm, because lead players need to play rhythm too....even when you are a lead guitarist, you wont be shredding during vocals, maybe some lead fills, but counter rhythm parts to the rhythm guitarist will be your job too usually.

Everyone wants to focus on shred guitar and it might impress people at first but eventually it will get old when you know nothing else.
Ok, you can't really 'shred' unless you know at least some scales and modes and how they work in the context of music, ie over what chords, chord changes, what notes clash, if you want dissonance or not and so on.

I personally learned a lot of 'shred' type songs in my first 2 years and this essentially improved my technique through learning.

After which, I began practicng the required techniques, doing exercises in isolation in order to gradually become more fluent and quicker. Sweep picking in particular took time in isolation.

As I was learning these exercises I picked up the minor, major, harmonic minor and phrygian dominant scales/modes and from this built up my repetoire of modes and later learned pure music theory.

Essentially there is not one way of improving and becoming a 'shredder', you need to gradually build up your technique and theory (as they go hand in hand) in order to become better.
Learning the theory is definitely very useful. The earlier you start doing it, the more you'll benefit in the future. I've definitely suffered trying to learn the theory 10 years after I started learning the guitar.

If you really want to shred, practice doing something useful like scales. I'm a big Satriani fan, and it's clear watching him that the numerous scales and patterns are so wired into his brain, that he doesn't have to think about which notes he playing to know he'll play something that goes with the music.

Learning to improvise can be really really hard.
For me the main problem was not giving up when what I improvised sounded like crap.
But then when we listen to music, we generally listen to experts, not someone learning.

When I started taking lessons, one of the first things I was taught was how to play the A minor pentatonic shapes all the way down the guitar neck, and a few exercises to help me remember the notes.
Then I got an A minor blues backing track (loads on youtube), and just play away with the notes of the scale. As I said, it'll probably sound crap at first as you try random notes, but eventually you'll figure out what sounds good.

The same applies to learning all the other scales really.

As freepower said, writing good music is way more important than technically impressive but rubbish sounding stuff.
Exercises have their purposes, but what I find helps more for overall playing ability is:

1. Learning theory, so you understand what you're doing

2. Learning songs, so you can get used to some licks you can use in your own playing, and also as exercises

3. Improvising, so you learn what sounds good together to your ears.

If you just practice exercises over and over, all you will get good at is playing said exercises, which is pretty much useless. Nobody wants to hear someone run through a 3 note per string scale at 200 bpm over and over. Instead, practice sections of songs that you're having trouble with. For instance, if you're having trouble doing a trill in a song, use that trill as an exercise. It will help strengthen your fingers, improve your hammer ons/pull offs, and it will help you play the song.
Quote by Geldin
Junior's usually at least a little terse, but he knows his stuff. I've always read his posts in a grouchy grandfather voice, a grouchy grandfather with a huge stiffy for alternate picking.
Besides that, he's right this time. As usual.