Fourth generation (4G) cell phones (so-called "smartphones") promise to provide rich-content internet access through improved connectivity and seamless roaming. Convenient true Web access will mean that it's no longer necessary to create lo-fi versions of websites. On the other hand, the cell phone interface favors a different way of surfing, where users have access to widgets and aggregated content through a single application. Typing in URLs or performing searches is less convenient on a phone, so sites will have to optimize themselves to either appear in popular aggregation hubs, or bundled with applications that perform a service.
Next Generation Localization
4G networks also herald the next step in localized searches. A mix of GPS functionality, street level imaging and records of physical addresses will lead to what experts have called "augmented reality." You'll be able to look through your phone's camera to not only see whatever the lens is pointing at, but the web addresses, contact information and other online information associated with whatever you see. There are already some primitive applications that do this, and in time this will become a routine way of meshing the Web with everyday life. Businesses will need to find some way to stand out in the barrage of information, particularly in dense urban areas.
The Real Time Web
Twitter provided the first taste of the real time public Web. SMS broadcasting and services like Google Wave will finish the job, providing up to the second information on popular sites and trends. Google has already listed real time search updates as an objective. As a result, future website promotions will have to be far more dynamic than they currently are. SEO experts will need to provide a stream of regular content and buzz to keep sites in the evolving conversation.
Web semantics (the relationship between words and their meanings) is in its infancy. The ultimate goal is a search engine that not only indexes data, but actually understands what it is, at least in relation to search queries. As search engines improve title tags and other coding signals (meta data, CSS structure) will be less important than the overall "tone" of the content -- whether it seems to have a strong or weak relationship with its target search term. Search engines will understand synonyms and slang better. This puts the focus back on content over coding.
Mashups (user generated combinations) of sites and services are currently delivered in a "top down" fashion via applications and social bookmarking sites such as Digg. Eventually one or more generalized applications will evolve that not only make it easy for the average person to mash up content, but may even automate the process based on the user's search history. To get noticed, sites will have to find synergy with others to form vertical communities.