I am not a tax attorney or an IRS guru, so take the following with a grain of salt. I'm new to the royalties business, but a quick search of the Amazon Community shows that Amazon sends out 1099s for $10 and more. See the last of three entries at http://forums.kindledirectpublishing.com/kdpforums/thread.jspa?messageID=46344딈 which purports to be answered by a KDP representative.
As for the IRS website, here's a good legal analysis from 2004 where a publisher sends the royalties to the agent who then sends them to the author (after each has taken their cut): http://www.irs.gov/irb/2004-20_IRB/ar08.html. Still the author pays taxes on the gross amount, not the amount s/he receives in the end. In the article, the writer states that in 2004, "the royalties paid by the publisher exceeded $10." That seems to be relevant from 2004 on through the present.
Per the instructions for Schedule E (referenced on line 17 of Form 1040 re royalties), here's an excerpt found at http://www.irs.gov/instructions/i1040se/ch02.html#d0e477:
Royalties. Report on line 3b royalties from oil, gas, or mineral properties
(not including operating interests); copyrights; and patents. Use a separate
column (A, B, or C) for each royalty property. If you received $10 or
more in royalties during 2011, the payer should send you a Form
1099-MISC or similar statement by January 31, 2012, showing the
amount you received. Report this amount on line 3b. If you are in
business as a self-employed writer, inventor, artist, etc., report your
royalty income and expenses on Schedule C.
Based on the above, ignore line 17 of the 2011 tax form 1040, for reporting of royalties and asking for the attachment of Schedule E, Supplemental Income and Loss, and use Schedule C instead for reporting author royalties.
For the Indie-pubbed authors, await those 1099-MISCs forms--even though we do not attach them to the 1040, like we would for a W-2. Per the IRS website, we should receive them by January 31.
Ahem. And I was expecting a refund this year, so I won't be getting it in January.
Good luck, all!