Now that WordPress.com is selling themes, it needs to be aware of misleading advertising and adopt a policy concerning whether it will tolerate such advertising. It has come to my attention that one of the major vendors of the premium themes on WordPress.com (it has six of the 23 premium themes available as of 12/2/11) is stripping out a lot of functionality in the themes it is selling on WordPress.com without any public disclosure of that fact. I don't know if there is a technical explanation of this stripping. But there is clearly a significant difference between the same advertised theme sold on WordPress.com and for traditional webhosted site. In at least one case, the differences include stripped out SEO, sidebar manager, custom widget, and options panel. Given that until someone actually purchases the theme there is no way to find out about these omissions, this appears to be a classic case of bait and switch (as in thinking you're buying one product and then discovering you're getting a very different one).
Undoubtedly, the vendor has a good excuse for these omissions. But I'd like to point out another related misleading aspect of the vendor's advertising. When you purchase the theme on the vendor's website, there is no indication that if you want to use it on a WordPress.com website there is an additional fee; that is, that the vendor is really selling two versions of the theme: one for self-hosting and one for WordPress.com. Arguably, the vendor is only testing out selling its themes on WordPress.com and doesn't want to publicize the fact or commit to a marketing strategy. But that doesn't negate the fact that its currently marketing is quite misleading.
There is also the question on exactly what terms one is buying the themes on WordPress.com. All this information s omitted. For example, will the themes be updated with future WordPress releases, as is the expectation and clearly stated terms of other theme contracts? Is the WordPress.com version of the theme being used only as a promo, where the theme could be removed tomorrow? Will the purchaser have to pay again every time the theme is updated on the WordPress.com site? These policies should be disclosed. If not, I think WordPress.com may eventually generate a lot of ill will for WordPress.org. WordPress.org has an excellent brand. It would be a pitty to sully it with such misleading marketing practices.