Hmm. I started writing this and it has turned into a fairly long analysis...
I'm just making assumptions here, but it looks to me like some of the decisions about the EB/MM Petrucci model may have been made due to less-than-anticipated demand. What was going to be a full production model now looks like it will be a build-to-order model. Without heavy demand for the guitar, there's no point in ramping up huge production volumes. It looks like they may have shot themselves in the foot on this one by initially pricing it way too high for what looks like a Silhouette model without a pickguard. I would imagine the high price killed interest for a lot of people right from the start.
The "build to order" idea for the new Petrucci model is a good one, but it has its drawbacks as well. You can decide just how much "JP" you want in it... make it exactly the model he plays or make it more of your own guitar by picking your own colours, etc. However, it basically means the guitar won't be built until an order is received. How many stores will stock one for people to try? This could negatively affect sales, which in turn will drive up the price.
I think the reality is that Petrucci's fans are a very small market. (Before coming to Jemsite, i hadn't ever heard of Petrucci or Dream Theater, other than their mentions in Ibanez and Yamaha catalogs.) Many, many people will look at a Petrucci signature model and say, "John who?
The other reality is that many people just don't want a signature models of today's flavour-of-the-month rock guitarist. I think they could have built a good production model with the new bridge and forearm scoop, and kept the price around $1000 or so... but then it'd be pretty much a double-cutaway Axis Sport with a few minor points of difference.
So many companies just don't seem to understand how to market a great signature model that appeals to a broad range of guitarists. JEMs and Universes have been reasonably successful at appealing to a moderately broad audience because of their feel, sound and versatility. But they still have pointy headstocks and body horns, which turns a lot of people off... even the more subdued VWH is still
a bit gaudy and extroverted in its personality, which limits its appeal. They're also limited by Vai's input on colours and finishes, which currently limits your choices to black and white.
Ernie Ball/Music Man kinda
know what they're doing, but kinda not. The EB EVH models didn't really take off in the market until Edward had gone to Peavey and the model was re-christened the Axis. Bringing out the Axis Sport and Super Sport were also keys to this strategy being successful... the more modest models were just as good, but not quite as flashy. Similarly, Peavey Wolfgangs have been very successful because they're more neutral in their style and can appeal to a broader range of players without them feeling like they're playing "that Eddie Van Halen guitar."
Both the Axis and Wolfgang are very versatile and great-feeling guitars that give the player a lot of finish options in a production model, and they've been very well received by the market. EB and Peavey also show sensitivity to different market segments by offering them in different levels, ranging from full-blown AAA maple-top versions (with carved tops on the Wolfgang) or a solid basswood model for those who want something a bit more modest, without compromising quality. They're lower-cost models without being "cheap" models like the JEM 555 and JS
-100. They've also marketed them with only a loose association with EVH, allowing the merits of the instrument itself, rather than its endorsee, to sell more guitars.
I don't know what the magic recipe is for a signature guitar to be a success... i think part of the equation falls on how established the artist is. George Benson, Pat Metheny, Allan Holdsworth and Edward Van Halen have all been around for 20 years or more, and have established themselves as having staying power. If people are going to spend big cash on a signature model guitar, they probably want to be pretty sure that it's going to stand the test of time, in terms of tone and aesthetics. Don't see too many people playing those neon-colored JEMs in public these days, do you?