My kids would miss me (at least at their present ages) 
I think such an occurance would have some noticeable effects on the market- some positive and some negative. On the positive side, a larger number of the better merchants would begin to do even more of their own research and recommendations. For every Grapes or Wine Connection out there going their own way and willing to do a lot of their own heavy lifting, there are dozens of equally large stores out there just happy to post the points of whatever got a good score and take orders until the juice is gone. So the concept of wine merchant would revert back to an earlier manifestation when many were more active in selecting and selling their own stock. Some at it now would stretch their wings and soar, while others would close up shop or go back to focusing on jug wines and Absolut exclusively.
In this same regard though, I think it would have more of a negative effect in concentrating even further the fine wine market to fewer players in major urban centers, where the density of population would provide the cash flow to help fund the travel that would be required to develop the expertise to select at a high level. This is particularly true of new vintages coming down the line (particularly in a limited production area like Burgundy), where someone is going to have to taste the wines before they come into the pipeline, so as to know what is wanted in time to have a chance of tracking them down. A subscription can offset a lot of travel costs- particularly where a merchant is further outside the major metro areas and may have less ready access to a wide array of wines at the distributor level- or is further away from major wine-producing regions and incurs heavier costs in terms of travel.
On the positive side (at least IMO), you would probably have a dramatic decrease in the number of “engineered” wines made to hit certain sweet spots for focus groups or critics, or at least the numbers would not continue to grow exponentially. But less well-known regions would have a harder time competing against the tried and true areas like Bordeaux and California, and a lot of interesting wines might go begging for an audience. And it is awfully hard to imagine a renaissance like we are witnessing with small grower Champagne having even a remote chance of success in the future without some critical push behind the wines. Very few merchants- even with the positive reviews of many of these growers- are willing to champion them to their customers, when they can just stack up a handful of Grandes Marques and treat Champagne as a commodity that sells itself- which in so many markets is exactly what happens.
But the original intent of the post was on a personal purchasing level, and I noted that most responders have sufficient experience and deep enough cellars to have little need today of wine publications. But you have to ask yourself honestly how much of your current base of knowledge was at least directed by what you may have read previously. Of course one has to separate the wheat from the chaff in terms of what you personally like after tasting various recommended wines- but for the vast majority of wine collectors out there, I think that in their fundamental years of building a cellar, reviews were useful and important. For my own part, I owe a tremendous debt to Robert Parker, Clive Coates et. al., as in my earliest years in the trade, their writing about regions, producers and wines that I was fairly unfamiliar with sparked an interest in getting to know these wines. As a junior staff member, I would have had no opportunity to travel on the company’s dime for many years to come (and certainly did not earn enough to finance my own travel- ask any junior clerk what he or she makes- its not a pretty number), but learned plenty about various regions and their wines long before I had moved far enough up the food chain to be sent on buying trips, and I have to think that there are plenty of young members in the wine trade today whose experience mirrors my formative years. Similarly, plenty of young collectors gain potentially valuable information from publications.
I am not trying to justify the existence of my journal, but simply to point out that even though one may have come out into the light at the far end of the tunnel after years of tasting and collecting, and to no longer have much use for wine publications, there are plenty of younger folks that may have recently discovered the magic of wine and where publications can still be quite meaningful. For this generation of potential future wine collectors, one of the biggest issues that faces them is the cost of wines these days, as I cannot imagine a lot of junior sales clerks that can go out and stretch to buy that odd bottle of mature Chave Hermitage or Chateau Latour these days (as I was able to do when I was first learning the business). I would assume the same applies to younger collectors (outside of young buck traders on Wall Street during bull markets), who may end up with a few prized, high end bottles in their collection, but most will be relying on critical press on the wines in selecting them, rather than opening a few to see what they like at their current price levels. In this regard, a little accurate knowledge can still go a long way.
Best,
John