According to the Ashkenaz custom, the Haftarah for this week comes from Yeshayahu (6:1-7:6, 9:5-6). The Levush (685) explains the connection to parshas Yisro:
In our parashah, we have the greatest revelation in history- Mattan Torah- when Hashem gave us the Torah, and Klal Yisroel witnessed Hashem's glory and experienced prophecy.
The Haftarah speaks of the prophecy of Yeshayahu about the Merkavah, the Heavenly Chariot, where the angels express their tribute to Hashem.
Yeshayahu's prophecy was similar to the prophecy at the giving of the Torah; thus, we read about it this week.