Whether you believe it's a conspiracy or a money grab, share buyback is exactly what Apple should do to increase value for shareholders. The stock is currently undervalued and any company would be wise to buy back its own stock when they can on the cheap (and have billions in cash lying around).
Since Icahn has pumped in, it is better to temporarily reduce the buy back, and wait till he finishes with his dump operation, which is never longer than 3 months, then increase the buy back to get the lowest buyback price possible.