V8 faster than Lua-JIT sounds like a really bold claim. AFAIK it is the other way around, with a factor of 3x.
Now cron can do directly in the database. The results you can obtain using REST request (with gzip is very less traffic). On the javascript there is a huge amount of libraries, such as Crypto, if desired, there will be templates to insert. When I finish the beta, it will be possible to write map / reduce function on the clusters. The differences will be very much.
Also, keep in mind that I wrote Lua-JIT, not Lua. There's a big performance difference between them too.