Doing a little research and these numbers seem pretty disappointing.
The devices actually were available for pre-order on September 1st and had sold 250,000 by Mid October. So sales over the last two months was around 750,000 units or about 375,000 per month. that's XMAS time so the last two months could be the best two months of the year.
Apple never released unit sales for the first generation of Apple TV, however one financial analyst, Gene Munster of Piper Jafray last year predicted sales of 6.6 million units in 2009, up from about 2.1 million units in 2008.
So they sold over 500,00 units per month in 2009 if Munster's numbers are accurate.
That suggests to me that new ATV sales may be lower than old ATV?????