I disagree....
Microsoft is the masters of "assimilation", starting with the
first and most popular multi-tasking program called Desqview. Then Windows went on to make "road-kill" out of Netscape, Eudora, Word Perfect, Lotus 123, Winamp (and at least a half other programs that Media Player ran over.)
The last couple releases have included features like Windows Defender that is
on the way to knocking out Ad-aware and other malware/spyware programs, the ISO burning option and option to burn music in Media Player knocks out Roxio, Nero and other media burning programs, and the System Image feature knocks out all but two backup programs (that clone a bootable backup.) You can also drag and drop files from your hard drive to an ftp site... so you don't need Ftp programs. Compression programs for .zip are no longer required. Bitlocker encrypts your data, putting third party encryption programs out of business.
There are only a few programs that Windows have not conquered. Norton. Panda and other AV programs have escaped - so far. Arj file compression is still alive. And Windows still can't read .pdf files. (BEWARE of Adobe pdf reader, it forces McAfee on your system without your permission.) And of course Google is not rolling over. So what will Microsoft to about Twitter? It's valued at one BILLION dollars.