Tech to Bring Backpacking Europe?

I am traveling for a few months in the spring, mainly in the UK, Germany, Switzerland, and Italy. I need to travel very light, but I also need to get online periodically to check in for work projects.

I've spent a lot of time in the UK, but I haven't been to Germany in years, and I'm completely ignorant about Italy. How difficult is it to get online? Should I plan on being offline when I'm not in a major city? Will I find Internet access in youth hostels, Internet cafes, etc?

For work, I use a Macbook Pro, mainly for Adobe Photoshop and InDesign; everything else I do is online. But the Macbook is too heavy to bring with me and I'm looking into buying something lighter. Will a tablet do the job?

If anyone has any experience to share, I'd appreciate it.