No, not even close. The Xoom is kinda like a oversize android phone. The only difference is, it can't make calls. Everything else a android phone can do it, the Xoom can do.
While I have to agree with the second poster's assessment I have to disagree that the Xoom is an oversized Android device. Sure, its running Android, but its a tablet Android experience and that vastly differs from the phone Android experience.
That being said, you sound like you want a desktop/laptop experience, but you need a new OS. I would blow away Windows and install Ubuntu or some Linux variant, if you know how to work with computers you should have an idea of how to accomplish this and Linux will better fit your use case than Windows.
Linux, especially Ubuntu, can be hassle-free if you set it up and don't tinker with it. Once you tinker, you can get some crazy power out of the software stack, but you can also make alot of newbie mistakes that end in frustration. If you install it, get it working the way you want it, and leave it alone, you'll never need anti virus or have to maintain the system at all. It will boot and run smoothly for the hardware's lifetime, provided it is supported. The only way to tell, is to give it a shot.
See http://www.webchicklet.com/computers/ubuntu/ubuntu-newbie-guide-first-24-hours-with-ubuntu/ for answers to alot of newbie questions.
I think the real question is whether you are going to only read, or do you also need to create or edit the documents, spreadsheets and slide presentations? If you are going to do anything other than very minor edits, I think you will find the touch keyboard on any device to be the limiting step. Even if you hunt and peck rather than touch-type, a real, full-sized keyboard will beat out a touch keyboard all day long.While you might get a bluetooth keyboard to connect to a Xoom, I think you'd need some other compelling requirements to go that route, when a Netbook will do the job better.
Perhaps Google's master plan for using the Xoom is to author documents using Google docs somehow. I haven't tried that yet. But otherwise, I was surprised that there wasn't even a simple text editor included with the Xoom. And the offering in the Market was not very impressive from what I saw. I settled on AK Notepad to create quick notes, but everything is saved in the app which requires an external "Catch Sync" account if you want your creations to go anywhere. I installed OpenOffice Document Reader v 1.3.0 from the Market, and it does read OpenOffice documents--well at least .odt documents and .ods spreadsheets. But it is a bit rough, doesn't yet support presentation files or the Microsoft Office equivalents like the full OpenOffice product from Sun does. There were some fee-based word processors in Market, but they sounded like they were developed for phones rather than tablets, and results are varied.
The other issue besides form factor, which may be the more important one for you, is the operating system. I second kazetsukai's suggestion to give Ubuntu a try. It will most likely work without a hitch on your Dell laptop, and the OpenOffice suite is included with the install, which will allow you to read and create all kinds of office automation documents. The support for Microsoft Office document types has also gotten very good. While you can no doubt find some fringe functionality in Microsoft Office that won't render properly in Open Office, and vice versa for that matter, most users don't use those advanced features, so it is generally not an issue. What you get in exchange is a very solid computing platform that won't keep changing because some company needs to refresh their revenue stream. Instead, it changes when the changes make sense. I switched my Dad from Windows XP to Ubuntu several years ago and his support problems dropped by about 98%. The only thing that took any effort was getting his accounting files out of Quicken and into GnuCash, and that only took about 15 minutes to get copied and working.
I don't see the xoom as a PC replacement...get the tablet from microsoft if that is what you want (it is a yawner to me but might suite you). But if you want to come over to the dark/fun side get a xoom...it is addictive. I bought it because I found myself going to the web more and more for info and comunication, but I am not a fan of the small screen of the droid phone (I can't imagine watching videos on that small a screen). So, the xoom is awesome and does a great job of keeping me in touch, informed and entertained. When I need to do work which involves office then I use my PC. If necessary I do have an app on my xoom that lets me do read and edit documents and I could buy a blue tooth keyboard, but I haven't felt the need for the keyboard yet in the few days I have owned the xoom. I will be writing 99.9% of my documents on my good old PC...but more than half of my Internet time will be on my xoom.
I think the Xoom is a great replacement for your computer for what you use it for. I just did the exact same thing! Just got the Xoom a week ago to replace my dying laptop. I can do everything and more on it that I do on my laptop, including ALL Microsoft Office apps (Word, Power Point, Exel) using the Android app Documents To Go. I create Power Point, Excel, and Word docs all the time on my Xoom. If you do a lot of typing, I would recommend getting the wireless full-size keyboard instead of trying to use the virtual one.
The only thing I still log on to my laptop for are the very, very few websites that do not recognize the Android browser or if I need to view something that requires Flash. But even that will soon be doable by the Xoom.
as for websites that do not recognize the droid browser and flash content, i dont have that problem. i can view any website/content, use flash, just download the adobe flash update, and use the xoom desktop browser mode setting.