The possibility is definitely true. the information came directly from randy falk (head of product development at neca).
Here's the deal:
prometheus series 2 (david8 and the deacon w/ hammerpedes) is 100% happening. In fact, series 2 just shipped to retail. david and the deacon should be on shelves late feb/early march.
Prometheus series 3, should it be released, will be comprised of Dr. Shaw and Infected Fifield (2 ups pictured in this thread). Series 3 is planned, but not at all a certainty. If series 2 does well enough...ie... sales hold firm or pick up a bit, series 3 will happen. If sales of series 2 slip anymore than series 1, series 3 will not happen. Randy said that sales for the prometheus line havent been poor, they just havent been where they want them to be. To quote randy, sales have been "marginal".
Assuming sales for series 2 and series 3 are acceptable, Neca has 4 more prometheus figures designed and ready to roll: Holloway w/ infected and uninfected heads, vickers, holographic pressure suit engineer, and holographic chair suit engineer.
I think its fairly realistic to assume that the line will get to series 3. Anything beyond that seems like wishful thinking to me. I certainly hope we get series 3. It would be a shame if Dr. Shaw never sees the light of day (how does that even happen?!).
Basically, if the line looks at all interesting to you, BUY the figures. I just preordered a case of series 2