Use of beginAnimations discouraged

I was informed recently by meronix that use of beginAnimations is discouraged. Reading through the UIView class reference I see that this is indeed true - according to the Apple class ref:

Use of this method is discouraged in iOS 4.0 and later. You should use the block-based animation methods to specify your animations instead.

I see that a large number of other methods - which I use frequently - are also "discouraged" which means they'll be around for iOS 6 (hopefully) but probably will be deprecated/removed eventually.

Why are these methods being discouraged?

As a side note, right now I'm using beginAnimations in all sorts of apps, most commonly to move the view up when a keyboard is shown.

//Pushes the view up if one of the table forms is selected for editing
- (void) keyboardDidShow:(NSNotification *)aNotification
{
    if ([isRaised boolValue] == NO)
    {
        [UIView beginAnimations:nil context:NULL];
        [UIView setAnimationDuration:0.25];
        self.view.center = CGPointMake(self.view.center.x, self.view.center.y-moveAmount);
        [UIView commitAnimations];
        isRaised = [NSNumber numberWithBool:YES];
    }
}

Not sure how to duplicate this functionality with block-based methods; a tutorial link would be nice.