Seidio is still selling the battery for $70, so Amazon's newly lowered price isn't part of an across-the-board reduction or anything like that. In fact, it wasn't too long ago that the online retail giant had it in stock for $63. Considering that Sprint's new extended battery retails for $55, paying a dollar less (plus no tax or shipping, depending on where you live) for more capacity isn't a bad deal at all.
Seidio's Innocell has been around since July, but here are some pics just in case your memory needs to be refreshed.
Incidentally, the Innocase Extended case (MSRP $29.95), which improves the look of the battery, is available for $23 on Amazon.[Seidio Innocell for EVO @ Amazon]