It took 5.5 million years for the Big Island to replace Kaua‘i over the “hot spot” (see below). It is probably reasonable to assume that the hotspot presently beneath Kilauea, Mauna Loa and Lo‘ihi will last for a little bit.

I’ll bet geothermal energy will last longer than fossil fuel oil.

Certainly, this island isn’t going to move so fast that we are in danger of losing all the heat and energy tomorrow. 

The ancient Hawaiians were wise; they knew how all this worked.

From the United States Geological Service’s page Hotspots: This Dynamic Earth:

According to Wilson’s hotspot theory, the volcanoes of the Hawaiian chain should get progressively older and become more eroded the farther they travel beyond the hotspot. The oldest volcanic rocks on Kauai, the northwesternmost inhabited Hawaiian island, are about 5.5 million years old and are deeply eroded. By comparison, on the “Big Island” of Hawaii — southeasternmost in the chain and presumably still positioned over the hotspot — the oldest exposed rocks are less than 0.7 million years old and new volcanic rock is continually being formed.

The possibility that the Hawaiian Islands become younger to the southeast was suspected by the ancient Hawaiians, long before any scientific studies were done. During their voyages, sea-faring Hawaiians noticed the differences in erosion, soil formation, and vegetation and recognized that the islands to the northwest (Niihau and Kauai) were older than those to the southeast (Maui and Hawaii). This idea was handed down from generation to generation in the legends of Pele, the fiery Goddess of Volcanoes. Pele originally lived on Kauai. When her older sister Namakaokahai, the Goddess of the Sea, attacked her, Pele fled to the Island of Oahu. When she was forced by Namakaokahai to flee again, Pele moved southeast to Maui and finally to Hawaii, where she now lives in the Halemaumau Crater at the summit of Kilauea Volcano. The mythical flight of Pele from Kauai to Hawaii, which alludes to the eternal struggle between the growth of volcanic islands from eruptions and their later erosion by ocean waves, is consistent with geologic evidence obtained centuries later that clearly shows the islands becoming younger from northwest to southeast.