A recent RAND corporation study addressing this question came up with several interesting findings. As expected, time pressures, externally imposed regulations and threats to the stability of income were negatives. No definitive patterns emerged about the impact of the Affordable Care Act (ACA) perhaps, according to the authors, because it's too early in the game. Intrusive regulation has been increasing steadily for decades and the ACA may prove to be just another point along that continuum. But concerning the impact of proposed new models of health care organization (e.g. the ACO) in the ACA the authors were able to draw upon data from analogous models brought by the wave of managed care in the 1990s. Findings from that era pointed to a negative impact on professional satisfaction.
The report did cite a lot of frustration among physicians about the meaningful use requirements for EMRs (not a part of Obamacare). In general, data from the report indicate that physicians like the idea of the EMR in the abstract (think it has promise) but perceive many aspects of present day use to be impediments to professional satisfaction. Chief among these are poor communication of clinical information (downsides of templates and other automated EMR functions) and the loading on of clerical duties out of the scope of physician training inherent in the way the EMR is used. As such the EMR is perceived as a time consumer rather than a time saver.
For more on the negative impact of the EMR on professional satisfaction see this post at Health Care Renewal.