I have just been browsing the dictionary of Russian surnames by Ю. А. Федосюк. He too derives Шарапов from the Tatar word meaning "honourable".
The Tatar, Dinara Safina and "наша Маша" may therefore have more in common than just tennis. As a musician, I was also interested to confirm what I had deduced for myself a while ago, that the surname of the composer Рахманинов comes from the Arabic word, rakhman meaning "benificent" (one of the 99 titles of God in Islam).

The well-known name, Yusupov (Prince Yusupov who killed Rasputin), is derived, according to one expert, from the Nogai language. I gather the Nogai are a Turkic people, sometimes known as the Caucasian Mongols, who are Islamic by faith. It seems to me the surname must be based on the Arabic name, Yusuf which in turn comes from the Hebrew, Joseph meaning "the Lord increases".