Arahant Path Contrasted With Bodhisattva Path

I've always wondered what the deal is with Mahayana bodhisattvas and buddhahood. Here's a pretty solid explanation of the difference between the Theravadin Arahant or "disciple" (sravaka) path and the Mahayana Bodhisattva path, from The Foundations of Buddhism by Rupert Gethin.

According to Theravada, the four paths and attainments are those of the stream-enterer, once-returner, non-returner and arahant. These are the four levels of the Noble Ones.

According to Mahayana, there are five paths: of equipment, of application, of seeing, of cultivation, and of the adept. The path of seeing is equivalent to stream-enterer and is the first of the 10 levels of the Bodhisattva path. Once the path of seeing is reached, the bodhisattva has to develop six perfections, the path of cultivation. At the sixth level, the bodhisattva has reached the stage where he could attain arahantship if he chose to, but instead he continues developing the final four perfections, the path of the adept, up to buddhahood. During this final path he is born in the realms of devas or Brahma and already has many of the powers of a buddha (such as the ability to "manifest created bodies").

"The bodhisattva spends many aeons in samsara perfecting spiritual qualities, and, in the process, working for the benefit of sentient beings; eventually he becomes a fully awakened buddha, but only when the teaching of the previous buddha has disappeared from the world.

For the Mahayana buddhahood this final attainment occurs in the Akanittha (Sanskrit: Akanistha) realm, the highest of the Pure Abodes."