In my technical opinion the PS3 was too much too early as far as technology. The technology in the PS3 only became an appropriate price to sell in late 2007 so releasing later if they had to have both would have been better as history and the market has shown us that a lot of people would have simply waited for the PS3 to be released. Releasing sooner at a higher price just gave a lot of people the justification to jump ship as they could judge what the PS3 was about and decided at that point it was too expensive for their needs.
If it was released earlier/at the same time they should have dropped either the Cell or the Blu Ray drive. However as the former has proved itself more than the latter in my opinion as developers have made good use of the architecture I would say that as releasing later with better technology and mature Blu Ray drives was probably out of the question then releasing earlier without Blu Ray would have been the best alternative as it was Blu Ray moreso than the Cell which delayed the release as the Cell was ready in bulk much sooner.
I would say that a PS3 with no Blu Ray but with the Cell processor and similar architecture would have been the better bet as the Cell processor would likely be very good at procedural generation of game assets to make up for a smaller DVD capacity. However without the Cell and a weaker overall system technologically would not have justified Blu Rays inclusion as Microsoft was following the technology and the overall generation would have been a smaller technological leap than it was, so the production of high quality assets would not have required as much space.
Tease.