I like how we finally have a neck that goes well with the rest of Leapo's mockups.
The SP bars are far too subtle. They also need some graduations on them so you can see how much you really have (or at least the half-way mark like GH2 so you can see when you can activate). Preferably I'd have 8 graduations (so each graduation is one measure, and you get two graduations from each set of SP notes), with the half-way one darker. But with such think meters there isn't really enough space.
Also, gold for SP is very Rock Band.
EDIT: Can we not do a curved neck? That's totally Rock Band's thing, and it already looks quite RB.
EDIT: here's my idea - the song structure bar.

The whole thing would be slightly transparent (and generally better looking, of course). It would replace the timer at the very top of the in-game screen. Horizontal direction represents time. It tells you how far along you are in the song (the translucent red bar shows this) and you can also see what sections are coming up.
The separate boxes represent practice mode sections.
* The first box is the intro. As intros are quite rare, there's no special marking for an intro.
* The next box is verse 1. Verses are simply shown as a box with the number of the verse in it.
* Then it's the first chorus. Choruses are lighter and have a C in them, for obvious reasons.
* Then verse 2.
* Then the second chorus.
* Then - you guessed it - the bridge. Which has, surprise surprise, a B in it.
* Now the guitar solo. It's blue (matching the blue neck colour during solos in Rock Band - if we use a different colour then that would be reflected here). It would show whatever icon we use for "guitar" on it to show that it's a guitar solo (a drum solo would show the drum icon, of course).
* Chorus again. This one's twice as long.
* Outro. Same story as the intro - no special marking.
So now the player can see exactly what's coming up. He can also adjust his star-power planning accordingly. If the player knows that the choruses are very chord-heavy then he can save his star power for that. A new Expert player who's unfamiliar with the song would save his star power for the solo which he knows is coming up (I don't want to know how many times I finished a song with a full bar of star power, which I was saving for the non-existant solo, when I first played Expert on GH2).
Also this could be displayed above Azzco's results bar, giving some meaning to the position in his bar. (so instead of knowing "I missed over there" you know "I missed at the beginning of chorus 2").
EDIT: potential problems with implementation. Some songs (especially in GH3) have weird section names from which it would be hard to determine these sections from. For most songs it would be easy to say "Any section containing 'chorus' but not 'pre' in its name is a chorus" but in TTFAF the choruses are called "So Far Away #". I guess putting it in the ini would work:
chorus_string = "So Far Away"
So it will mark any section containing "So Far Away" a chorus.