If may ask those that still believe in him one question. It would be what would it take at this point to doubt him?
An attempt to answer that question;
I believe the long term trend is still towards "The Rossi effect is real".
Rossi has come a long way. In Italy everything he did had a very amateuristic look and feel. His English was not the best, ditto his style of communication. In the last six years there have been disappointments, but he always has (partially) delivered on promises he made and i believe that this trend is continuing.
Skeptics will react with arguments like for example that the robotized factories, the donations to children with cancer and the sold plants are lies from Rossi that prove he is a conman.
I think that most of these arguments are besides the point (and most likely have explanations we will learn in due time). It is merely noise. The obvious trend of Rossi growing more professional and gaining more traction is what you should be monitoring. This is the signal.
The technological developments, the IH investment in itself, the info from the court documents, the outcome of the court case, Rossi's English, the Uppsala connection, the research papers, the announcement of two new presentations and so on and so forth, are all, proof for me that we are heading towards a situation where events will happen closer to each other. A climax perhaps.
In short, i would start doubting Rossi if the above described trend is broken. If he goes undercover, if he starts working on a different type of E-Cat and thereby is taking steps backward instead of forward, etc.
As of late i believe the we see a breakout on the upside of the trend. I hope Rossi can keep up this tempo and convince the world he has something.