Quite a loaded question, but I'll do my best to provide a succinct answer
Seam and JSR299 have taken huge strides in simplifying Java EE development especially within the context of web development. Many of the reasons people have strayed from the spec and flocked to frameworks like Spring are due to the complexities of developing applications using the standards. There were great improvements (many directly influenced by Spring and Hibernate) with EJB3 and JPA, but development of web applications has still been overly complex mainly due to the lack of a unified component model which these technologies directly address.
Java has been facing some serious competition from other technologies due to their simplicity and rapid development turnaround time. Seam and JSR299 have resolved many of the complaints surrounding Java EE development (especially in terms of a simplified programming model and rapid application development) and are bringing a lot of needed excitement back to the Java EE space. I'm a firm believer that by making it simple to develop an application using standard solutions we improve the Java community as a whole by creating a more competitive environment which in turn leads to greater innovation.