iPod sales hit 22.7 million in the Christmas quarter of 2008 and have been going downhill, with seasonal spikes, ever since.

The quarter that ended nearly three weeks ago is likely to continue that trend, according to the 43 analysts — professional and amateur — we polled in advance of our quarterly earnings smackdown.

For once, the two groups are in agreement. According to their median estimates, they both expect Apple to report sales of 8.39 million units in Q3 2011 — down 7.2% from the same quarter last year.

That’s not to say there aren’t disagreements. There is still a 2.5 million unit difference between the estimates of Wedbush’s Ralph Schackart (9.76 million) and Ticonderoga’s Brian White (7.21 million).

But the trend is clear. Although Apple (AAPL) still owns more than 70% of the MP3 player market, the company has shifted its attention to smartphones and tablets that also play music. Even the iPod touch, which according to Piper Jaffray’s Gene Munster has accounted for more than 50% of iPod sales every non-holiday quarter since 2010, is getting less love from Apple. This summer, for the first time since it was introduced, a free iPod touch is not being thrown in with every Mac purchased as part of the company’s Back to School promo.

Below: The iPod unit sales estimates we’ve gathered so far and the dates they were submitted. The Q2 rank numbers show how accurate each analyst’s estimates were last quarter (the lower the better).