Darwin predicted, based on homologies with African apes, that human ancestors arose in Africa. That prediction has been supported by fossil and genetic evidence (Ingman et al. 2000).
Theory predicted that organisms in heterogeneous and rapidly changing environments should have higher mutation rates. This has been found in the case of bacteria infecting the lungs of chronic cystic fibrosis patients (Oliver et al. 2000).
Predator-prey dynamics are altered in predictable ways by evolution of the prey (Yoshida et al. 2003).
Ernst Mayr predicted in 1954 that speciation should be accompanied with faster genetic evolution. A phylogenetic analysis has supported this prediction (Webster et al. 2003).
Several authors predicted characteristics of the ancestor of craniates. On the basis of a detailed study, they found the fossil Haikouella "fit these predictions closely" (Mallatt and Chen 2003).
Evolution predicts that different sets of character data should still give the same phylogenetic trees. This has been confirmed informally myriad times and quantitatively, with different protein sequences, by Penny et al. (1982).
Insect wings evolved from gills, with an intermediate stage of skimming on the water surface. Since the primitive surface-skimming condition is widespread among stoneflies, J. H. Marden predicted that stoneflies would likely retain other primitive traits, too. This prediction led to the discovery in stoneflies of functional hemocyanin, used for oxygen transport in other arthropods but never before found in insects (Hagner-Holler et al. 2004; Marden 2005)".
Those are “discoveries” after the fact. Now, give us a prediction about the next 10 genetic changes that will take place in human beings.<Predicting that discoveries will be made is not to predict the discoveries themselves!
Speciation may well involve some aspect of DNA management than the genes themselves, but it's not a consequence of readily identifiale changes in genes.