The strike will affect Hollywood in a multitude of ways. Late night talk shows will be the first ones hit and will likely shut down immediately. Soap operas and current series are next, but will probably make it through the year since they've filmed episodes in advance. The film industry is a bit better off as they'd been collecting new material over the past year in anticipation of the strike. However, once these films go into production problems will arise when the inevitable script revisions are needed.
Authors will feel the affects of the strike as well, both directly and indirectly. Probably the most direct affect will occur in regard to film options for your work. If your work is already under option but the term is set to expire soon, in most cases the licensee will be able to extend the option without paying an additional fee as a result of the force majeure clause found in almost all option agreements. This clause deals with acts outside of the parties' control which delay performance of the agreement, such as war, "acts of God", or strikes. Since producers engage screenwriters to develop a script based on a book in order to sell the project to studios, the strike prevents them from properly pursuing their option. In such cases the licensee can extend the option without payment for an additional period, typically 6 months.