I've heard rumors that Unilever is indeed working on a lower carb version of their Slim-Fast line and if they aren't it would be financially wise for them to start doing so.
OTOH, they could be hedging their bets that this is nothing more than a passing fad and will blow over in a year or two leaving them the king of the proverbial diet products mountain once again when former low carbers quit low carbing, regain the weight and are once again looking for a product to help them lose weight.
Being wholly realistic, to a lot of people low carb is nothing more than a way to shed a few quick pounds and they never intend to make it a way of life when they begin such a program (their mistake). We all know what is likely to happen when they reach their weight loss goals and return to the way of eating that got them in need of losing a few quick pounds in the first place and Unilever, I'm sure, will be right there to say, "We told you so...here, have a Slim Fast".