You're right. Support is collapsing. As of January 6-7, 53% of respondents favored the stimulus package and 36% opposed it. As of January 27, 52% favor it and 37& disapprove. The margin of error is +/- 3%.
http://www.gallup.com/poll/114028/Sl...ulus-Plan.aspx
Also according to Gallup, Obama's approval rating has ranged from a low of about 62% in early December to a high of 70% prior to inauguration, 68% on inauguration day, and 66% today. Obviously another area where he is slipping badly.
Based on historic experience, I would expect Obama's popularity to go through many swings but generally to decline from current levels in the absence of extraordinary events.