To be honest it is easy to do multi-sub domain certificates already. Wildcard certificates will only make my life more simple. But unless you need a huge number of sub domains, or dynamic sub domains, it's not really going to change that much.

If anything it will reduce the strain on their servers. Instead of authorising subdomain by subdomain there will be a single authorisation by domain.

It's possible, but a couple of points to consider:

1) Wildcards may have a net negative effect on total issuance if subscribers who were getting many non-wildcard certificates before replace them with a single wildcard. I'm not sure this will be the case, but it could be. I expect wildcards will help move many more sites to HTTPS - perhaps just with fewer actual certs.

2) Wildcard validation from Let's Encrypt will be restricted to DNS validation, and many people don't have the ability to automate modifications to their DNS records. That being the case, it will be a bit more difficult to validate for wildcard certificates than for non-wildcards.

uh, why?

shouldn't it get less again? if i use ~8 certs for different servers, i could just get a wildcard for my domain and be done with it...?