There is definitely still a lot of skepticism in the program - however some provisions that have become clearer as the program reaches execution phase should give some comfort to skeptics.
Again, to reiterate fundamentals, this US program is far better than similar programs - unlike the UK Asset protection Program for bad assets where exposure is not clearly ring-fenced, the US program has definite quantifiable upside and downside. Also, executive compensation restrictions for entities which invest money and avail government funding/debt for the same ensure asset managers clearly segregate agency functions and principal functions.
However, the complex structure (of both the legacy loan and securities programs) and other parallel government initiatives in the credit markets make program administration tricky if not tough.
For example, the Home Mortgage Modification program under which the Treasury has earmarked money for mortgage servicers (see article) will pose questions on applicability of the subsidy to investors in the PPIP program - since the subsidy is targeted at servicers and not loan/asset owners. Similar programs would potentially increase book value of the loan pools and raise acquisition price for PPIP investors, but the actual subsidy is tied to servicers and would be lost to investors unless the servicing contract with the same servicer is retained durign period of ownership.
Another example of uncertainty/complexity is the extent to which ongoing asset management strategies for the pool (as employed by selected asset managers), and management of the program in general would be subject to Treasury oversight, is not known yet. Some or all of these will become clearer as the program unfolds, but some amount of fluidity is unfortunately bound to prevail.
There's a lot of money and time invested in this program - and enough and more stakes for all parties to ensure it helps revive the distressed securities market and hence credit markets in general! The onus is on the Treasury to continue effective articulation of program logistics/operating model and also interlinkages with other credit market initiatives.