As a long-time skeptic when it comes to most conspiracy theories, I don't particularly want to buttress the theory that "big business is quashing new technologies". However, it's not unreasonable to argue that big business (especially big oil companies) would be much happier with high-temperature Tokamak-type fusion than "cold fusion".
High-temperature fusion will (at least initially) cost billions of dollars in capital costs for each giant power plant, even when it finally becomes economical (and that time is decades away). So big oil companies need not fear serious competition for quite a while, and then they would likely be the ones making the huge capital investments during a slow phase-over. High-temperature fusion follows the classic model of big government R&D expenditures which big business subsequently exploits.
Cold fusion, on the other hand, would be what is called a "disruptive" technology. It could happen relatively cheaply and quickly, possibly by new companies or ones not currently in the energy business, and it would obsolete much of the existing investment and energy infrastructure. So no, I do not think the giant corporations who currently dominate energy production and distribution would be too pleased with a technological breakthrough. That doesn't mean they could successfully scuttle cold fusion's development, but they would not be happy campers.