Are There Jobs in Web Applications Development?

Yes, but, Why? I think because:

1. Many of the fastest-growing technology companies (facebook, twitter, google, salesforce, and tons of other small companies) are web application companies.
2. Old technology companies like Microsoft, IBM, SAP, and Oracle are "moving to the cloud", which means they are moving many of their applications from the desktop to the web.
3. Many other regular companies (banks, insurance companies, etc.) are converting their old desktop-based (Visual Basic) software to web applications because of demand from their clients and employees. Others are keeping the old apps but making all the new apps as web apps.
4. The iphone and android devices are largely used as communication devices (yelp, facebook app, evernote, etc.) that talk to a web application. Well, that, and as really expensive and really annoying to use Nintendo DSs.

One data point is stackoverflow's recent survey which showed that 40% of stackoverflow users describe themselves as Web Application Developer (question 7). That is a huge number. I think its a bit inflated due to self-selection bias (web app developers are more likely to read the blog).