I recently attended a conference dedicated to Italian autochthonous varietals -- vines native to the various Italian regions. It turns out Italy has more than 3000 grape varietals, which is more than any other country in the world. Of these, most are very local strains that simply grow in people's vineyards; they go into the local blend and that's that. About a thousand are instead planted and grown intentionally, and of these thousand about 500 have been studied and catalogued. About 50 of these 500 account for the bulk of Italian wine production. The remainder represent a terrific opportunity: while it's true that many are nondescript and wouldn't be missed, it's just as true that some have tremendous potential and are simply awaiting discovery.
For example, Donatella Cinelli Colombini is best known for her Brunello di Montalcino. However, the villa she lives in is outside the Brunello production area, so she has begun to experiment with Foglia Tonda, an old varietal that was discarded by the farmers following the phylloxera outbreak a century ago because it was less productive than Sangiovese and more difficult to grow. It has taken her several years to bring her Foglia Tonda vineyard into production, but the results are most impressive, especially considering the youth of the vines: There's tremendous power and concentration, and as the vines enter into maturity in a few years' time finesse will arrive as well. In a similar light, Sagrantino, an Umbrian grape and wine produced around Montefalco that is now attracting world-wide attention, was completely unknown outside of Umbria until Arnaldo Caprai began to experiment with it about 15 years ago. The same holds true for Teroldego Rotaliano, an obscure red grape from Trentino; Elisabetta Foradori began growing it with care about 15 years ago, and now both she and other producers who have followed her lead are earning awards for their Teroldego Rotaliano.
These are all vines capable of yielding good to excellent wines on their own. But Italy has an equal abundance of what are known as uva complementari, lesser varietals that cannot stand on their own, but contribute to a blend, say by adding color, floral accents, roundness, or some other facet. Their importance is difficult to overestimate, and Chianti provides a good example of why: Tuscany's great red grape is Sangiovese, which is capable of terrific refinement and finesse. However, it's also temperamental, and if the vintage isn't letter-perfect can have aggressive tannins or marked acidity, or be lacking in color, or be thin, or whatever.
Enter the uva complementari, which help fill out the Sangiovese; when Baron Ricasoli developed the original blend in the mid-1800s he used Canaiolo, another red grape, to add grace and tame the unruly side of his Sangiovese, and added a little Malvasia del Chianti, a white grape, if he wanted added zest in a wine to be drunk young (no white grapes in the wines he laid down). Some people are still using Canaiolo, though many Tuscan vintners dropped it in favor of Cabernet or Merlot in the 70s and 80s, in part because the French varietals are more consistent and therefore easier to work with, and in part because the French varietals added an international flavor to the wines that helped them penetrate foreign markets.
However, in recent years there has been a shift back to other autochthonous varietals, for example ciliegiolo and colorino, both of which provide color, or mammolo, which adds hints of violets to the bouquet (mammolo is Tuscan vernacular for violet).
Why would someone abandon the easy-to-use French varietal in favor of a more intractable Italian varietal? Primarily because though the French varietals generally give good results, with rare exceptions (the Cabernet of Bolgheri comes to mind) the wines made from them are generic -- one can find very similar, equally good French varietal-based or containing wines made elsewhere, often at considerably lower prices. The Italian varietals, on the other hand, are usually quite local, and in some cases grow well only in small areas. For example, Nebbiolo grows well around Alba, in a couple of places in Northern Piemonte, and in the Valtellina. So far, all attempts to produce really good Nebbiolo-based wines elsewhere have failed, and this means that the producers in those regions where Nebbiolo does well have something unique to offer.
The international wine trade likes good unique wines, and this gives those who can produce them a means to survive and prosper. With the thousands of Italian varietals still awaiting evaluation, there are certainly many more diamonds hidden in the rough.