The alpha has been published in January. You can use it if you want, at your own risk.

The devs are working hard and the beta is likely to come in 2018. People think naively than increasing the block size will change something. It will in the short or mid term, but not in the long term and you can't keep increasing the blocksize. There needs to be a permanent, well implemented solution and that's what's coming and why it's taking so long.

Blocksize increase alone is not sustainable.