Quill does not hold that you cannot tax items sold from other states and brought into the taxing state. It merely hold that the selling entity must have sufficient nexus to X state to justify the imposition of a sales tax.
However, fundamental to Quill was the burden that calculating a sales tax would impose on the retailer. In the times of Quill, incidental sales (in the case, less than a dozen over several years) to customers in North Dakota were not enough to justify the burden of imposing a sales tax; it would have cost Quill more to figure out the sales tax owed than Quill would make from the sale.
But technology has changed. The concerns raised in Quill are non-existent today; it is trivial and dirt cheap to calculate and collect a sales tax for all taxing jurisdictions in the U.S.
Amazon knows this; that is why it has always backed down when states threaten to pursue this issue in court (i.e., NY, Cali, and Texas). Indeed, Amazon now offers a sales tax calculation service to smaller etailers.
Note that most legal commentators agree that Quill could easily (and probably would) have gone the other way if the catalog company in the case had sold to more than a handful of customers in North Dakota.