The Shapeshift variant druid from Player's Handbook II, pp39-41, replaces wild-shape and animal companion features with a swift action shapeshift into different forms, with different capabilities.
The ability does not inherit rules from any other form-changing abilities, and mentions only once what happens to gear worn or carried:
…All your held, carried, or worn gear melds into your new form and becomes nonfunctional until you return to your normal form…
He has the option to change to another shapeshift form directly, or to his normal form. So, presuming that a character has shapeshifted into a form, then dons gear, such as barding or armor, or a magical necklace, what happens to the gear when he changes form, to either his normal form or to another shapeshift form, again? If the gear melded into his new form, which form is his 'normal' form regarding that gear? When it does 'unmeld' where is it?
What I'd like to have happen is that the gear worn in a shapeshifted form melds into his new form, or normal form, until he returns to the shapeshifted form again, but I see no rules either way.
Best Answer
(Couldn't find explicit RAW to support this)
You are correct in stating that 'the ability does not inherit rules from any other form-changing abilities', nor is it labeled as similar to any.
However, comparing the other common shape change rules, you see the following (all emphasis mine):
Alternate-Form and Change Shape Monster Abilities
This is clearly different than the Shapeshift class feature. Note that there's no "melding gear" effect here.
Standard Druid's Wild Shape
This is in essence the same behavior as the Shapeshift variant, with the added explicit statement that gear obtained in the 'non-true' form falls off when you revert to your true form.
Transformation Spells such as Alter-Self, Polymorph and Shapechange
Right, so again we see the "melding gear" effect, and again, it applies only to gear carried in the true form - anything gained in an alternate form falls off when you revert (unless you can wear or hold it in the same way in both forms).
From these examples I see two possible interpretations (which one you use basically boils down to your GM's call and your group play style):
The "Power Gamer" Interpretation
Other mentions of the 'melding gear' effect explicitly state it applies only to the true form, while this is absent from the Shapechange variant. By taking this omission as intentional, you can conclude this effect works on any form - effectively allowing your druid to have a different inventory for each shape. Moreover, you may claim that the Shapechange variant druid doesn't really have a true form, as he can stay indefinitely in any of his forms...
This interpretation makes this feature much stronger, and will allow for less cumbersome gameplay if you intend to use magic items to buff each form (as your druid won't have to worry about donning armor and wearing amulets, belts and rings every time he changes - as well as where to carry them the rest of the time...).
However, it can easily be abused, turning your druid to the party's pack-mule / walking bag of holding...
The "If it Quacks like a Duck" Interpretation
There seems to be two different themes for shape-changes in 3.5E - one without the 'melding gear' effect (which applies mostly to monsters), and another with it - which applies mostly to PCs and NPCs. All other descriptions of this effect always make a clear distinction between the 'true form' and alternate ones, and apply the effect only for transformations from the true form. It seems more balanced to apply the same treatment for the druid variant too - especially as this feature's description does use the term 'true form', hinting that regardless of how much time he actually spends in that form, the druid still have one.
This option is less powerful, but has less impact on game balance. It may force your druid to invest in wild-armor which changes shape with him, and perhaps have some of his alternate form's gear carried by other party members.
Either way, I'd ask the GM to allow for items relevant for both shapes (such as magic amulets or belts) to remain 'unmelded' and functional across shapes, so you don't need to have several copies of each (for option 1), or depend on an ally to dress you up before and after every change (for option 2) - of course, they may cost more than standard magic items for this additional ability...