vendor tracking design flow

[Neal Becker]

I'm pretty happy with my current flow.  The objective is to track an upstream 
package, but apply a few of my own patches.

Currently, I have 2 named branches:
vendor: (upstream)
default: (with my patches)

With each new release of vendor-x.y.tar.gz, the flow is:

tar xzf .... (extract new files, into directory vendor-x.y for example)

cd default-repo (goto my current repo)
hg update default
cd ..
cp -al default-repo/.hg vendor-x.y
cd vendor-x.y
hg addremove
hg ci
hg update default

I guess I'm just wondering:

1) Is there some 'better' way to accomplish this?

2) I'm a little bothered that it goes 'outside the system', using cp -al 
blah/.hg.  It would be nice to have something entirely within hg, like:

hg new-source vendor vendor-x.y.tar.gz